Practical consequences of the validation of a mathematical model in assessment of partial androgen deficiency in the aging male using bioavailable testosterone

Partial androgen deficiency or the andropause in the aging male is a complex clinical and biochemical entity that needs to be analyzed at two levels of the constituent structure: the 'deep structure' should come to light with more intensive research, while the 'surface structure' holds the attention of investigators who focus on hormone measurements in the blood to help diagnose the andropause. In this study, it is recognized that bioavailable testosterone decreases progressively during the aging process. This physiological decline may be so important, or so close to castration levels, that aged men may experience numerous symptoms of hypogonadism. The assay for bioavailable testosterone was indirectly validated with a set of equations derived from our knowledge of the law of mass action at equilibrium, as proposed by Vermeulen and colleagues in 1999. With this mathematical model, we have shown that calculated free testosterone was highly correlated with bioavailable testosterone. It is therefore concluded that the evaluation of aged men's androgenicity should rely on at least one of these free testosterone assessments (bioavailable or calculated free testosterone) for the sake of reproducibility in the construction of the 'surface structure' of the andropause in the coming years.     

Long-term low-dose dehydroepiandrosterone replacement therapy in aging males with partial androgen deficiency

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) age-related withdrawal is very likely to be involved in the aging process and the onset of age-related diseases, giving rise to the question of whether preventing or compensating the decline of these steroids may have endocrine and clinical benefits. The aim of the present trial was to evaluate the endocrine, neuroendocrine and clinical consequences of a long-term (1 year), low-dose (25?mg/day) replacement therapy in a group of aging men who presented the clinical characteristics of partial androgen deficiency (PADAM). Circulating DHEA, DHEAS, androstenedione, total testosterone and free testosterone, dihydrotestosterone (DHT), progesterone, 17-hydroxyprogesterone, allopregnanolone, estrone, estradiol, sex hormone binding globulin (SHBG), cortisol, follicle stimulating hormone (FSH), luteinizing hormone (LH), growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels were evaluated monthly to assess the endocrine effects of the therapy, while β-endorphin values were used as a marker of the neuroendocrine effects. A Kupperman questionnaire was performed to evaluate the subjective symptoms before and after treatment.

The results showed a great modification of the endocrine profile; with the exception of cortisol levels, which remained unchanged, DHEA, DHEAS, androstenedione, total and free testosterone, DHT, progesterone, 17-hydroxyprogesterone, estrone, estradiol, GH, IGF-1 and β-endorphin levels increased significantly with respect to baseline values, while FSH, LH and SHBG levels showed a significant decrease. The Kupperman score indicated a progressive improvement in mood, fatigue and joint pain.

In conclusion, the present study demonstrates that 25?mg/day of DHEA is able to cause significant changes in the hormonal profile and clinical symptoms and can counteract the age-related decline of endocrine and neuroendocrine functions. Restoring DHEA levels to young adult values seems to benefit the age-related decline in physiological functions but, however promising, placebo-controlled trials are required to confirm these preliminary results.     

Testosterone supplementation: what and how to give

Several epidemiological studies have demonstrated a gradual decrease of serum testosterone with aging in men. A considerable number of men will experience hypogonadal androgen levels, defined by the normal range for young men. Thus, in addition to the long-standing use of androgen replacement therapy in the classical forms of primary and secondary hypogonadism, age-associated testosterone deficiency has led to considerable developments in application modes for testosterone. Since oral preparations of testosterone are ineffective, due to the first-pass effect of the liver, or, in case of 17 α-alkylation, cause hepatotoxicity, intramuscular injection of long-acting esters, such as testosterone enanthate, have been the mainstay of testosterone therapy. However, the large fluctuations of serum testosterone levels cause unsatisfactory shifts of mood and sexual function in some men; combined with the frequent injections, this delivery mode is thus far from being ideal. In contrast, the transdermal testosterone patches are characterized by favorable pharmacokinetic behavior and have proven to be an effective mode of delivery. Safety data over 10 years indicate no negative effect on the prostate. Nevertheless, the scrotal testosterone patch system is hampered by the application site, which is not easily accepted by many subjects; the non-scrotal patch has a high rate of skin irritations. In view of the drawbacks of the currently available preparations, the most recent developments in testosterone supplementation appear to be highly promising agents. Androgen, which has been available in the United States since mid-2000, will be introduced this year in most European markets as Testogel ® , a hydroalcoholic gel containing 1% testosterone. Doses of 50-100 mg gel applied once daily on the skin deliver sufficient amounts of testosterone to restore normal hormonal values and to correct the signs and symptoms of hypogonadism. The gel has shown to be very effective and successful in American patients, who have benefited from its availability for almost 3 years. Furthermore, in phase II and III clinical studies, the intramuscular injection of 1000 mg testosterone undecanoate every 12-15 weeks has led to extremely stable serum testosterone levels for a prolonged period of time and has resulted in excellent efficacy. It is very likely in the future that these products will be the mainstay of testosterone supplementation. Whereas the indication for testosterone substitution for men with classical forms of hypogonadism is unequivocal, the use of testosterone in men with ageassociated hypogonadism is less uniformly accepted. Yet, the few studies addressing this question indicate that men with testosterone serum levels below the lower normal limit for young adult men and with lack of energy, libido, depressed mood and osteoporosis may benefit from testosterone supplementation. However, it should be kept in mind that the experience documented in studies is limited. Nevertheless, serious side-effects, especially in regard to the prostate, did not occur, with the longest study extending over 3 years.     

Diagnosis,pathogenesis and treatment of erectile dysfunction

Introduction: After middle age, some men show androgen-deficiency symptoms leading to so-called PADAM (partial androgen deficiency in aging males). We tested the oral form of testosterone, testosterone undecanoate (Andriol^®, NV Organon, The Netherlands), in men with PADAM and evaluated its efficacy and safety in Korean male patients. Methods: We included those patients with the clinical symptoms of PADAM who had decreased levels of serum total testosterone (< 2.8 ng/ml) or free testosterone (< 13 pg/ml). We excluded patients with biopsy-confirmed prostrate cancer, abnormal findings in digital rectal examination or prostate specific antigen testing (until prostrate cancer was ruled out), breast cancer, severe voiding symptoms and secondary hypogonadism. At the first visit, the International Prostate Symptom Score (IPSS), International Index of Erectile Function (IIEF) and Korean Andropause Questionnaires were administered; complete blood count, the lipid profile, and levels of total and free testosterone, prolactin, luteinizing hormone, follicle stimulating hormone and prostate specific antigen were measured and a digital rectal examination was given. Patients were administered oral testosterone undecanoate 160 mg daily for 3 weeks. The dosage was then decreased to 80 mg daily and changes in symptoms were assessed at every visit. After 3 months, serum tests, including testosterone, were repeated. Results: We evaluated 28 patients who had received testosterone undecanoate for more than 3 months. The patients' mean age was 56.1 (48-68) years. The score of the Korean Andropause Questionnaire changed from 56.2 ± 21.7 at baseline to 52.9 ± 21.3 (p = 0.03) after 3 weeks, to 49.3 ± 19.3 (p = 0.03) after 8 weeks, and to 46.5 ± 25.6 (p = 0.028) after 12 weeks. With respect to sexual function, mean IIEF scores were 37.2 ± 19.6 at baseline and 38.7 ± 19.2 and 40.2 ± 22.0 (p = 0.033) after 3 and 12 weeks, respectively. Serum total testosterone increased from 2.13 ± 1.20 ng/ml at baseline to 6.04 ± 3.08 ng/ml (p = 0.005) after 12 weeks, and free testosterone was marginally significantly changed from 8.60 ± 2.25 pg/ml to 11.40 ± 3.81 pg/ml (p = 0.13). However, there were no significant changes in liver function tests, red blood cell count or lipid profiles. There were no significant adverse reactions that led to the cessation of the administration of oral testosterone. Conclusion: Oral administration of testosterone undecanoate can improve symptoms of PADAM in Koreans. It may, therefore, be an appropriate treatment option with few adverse effects for PADAM patients.     

Quality-of-life issues in the aging male

This paper is based on a presentation given at the 2nd World Congress on the Aging Male, Geneva, Switzerland, February 2000     

Effects of androgens in men with the metabolic syndrome

The metabolic syndrome is well recognized as the association between obesity, elevated blood lipids, hypertension, hepatic steatosis, impaired glucose tolerance/diabetes mellitus type II and increased risk for cardiovascular disease. Recently, several publications have demonstrated that uisceral accumulation of fat seems to be more important than general obesity and that several endocrine disturbances should be included in this syndrome. The first observations concerning the importance of body fat distribution and endocrine disturbances, however, were made in the 1940s and later confirmed by further research. Concerning the endocrine disturbances, we have specifically found that abdominal, i.e. visceral, type of obesity is associated with low levels of sex steroids in both men and women, increased Cortisol activity as well as a blunted growth hormone action. In several hormonal intervention studies, we have also demonstrated favorable effects on visceral obesity, insulin sensitivity, blood lipids and blood pressure. Furthermore, recent results from our research group have indicated that this complex of signs and diseases is associated with psychiatric signs such as mental stress, signs of melancholy and decreased life satisfaction. In order to explain better the possible pathogenesis of these risk factors and diseases, the term ‘the neuroendocrine syndrome’ seems to be more adequate. This article willfocus on important biological mechanisms in hormonal intervention strategies, especially androgen treatment, for patients with this syndrome.     

The aging male in the literature

The diagnosis of hypoandrogenism in the aging male is still difficult, since the symptomatology is aspecific and multifactorial, and it is unknown whether the androgen requirements of elderly men are the same as those of young men. Indeed, there are arguments for decreased (increased androgen feed-back sensitivity) as well as for increased (decreased concentration of androgen receptors) requirements in elderly men. In the absence of a reliable, clinically useful, parameter of androgen activity, we have to rely on plasma androgen level, an indirect parameter. In the absence of convincing arguments for altered requirements with age, we consider that the normal range of (free) testosterone levels in young adults is also valid for elderly men, the lower normal limit being 11 nmol/l for total testosterone and 0.225 nmol/l for free testosterone. There are indirect, suggestive clinical arguments for accepting these limit values. The diagnosis of hypoandrogenism in elderly males requires both the presence of clinical symptoms and decreased (free) testosterone levels. The best methods for determining free or bioavailable testosterone, are equilibrium dialysis and ammonium sulfate precipitation, respectively. They are, however, time-consuming techniques which are not easily automated. Calculation of the free androgen index (testosterone/sex hormone binding globulin (SHBG)) is not a valid method for male serum. Calculation of free testosterone from total testosterone, SHBG and albumin concentration, yields values that are in good agreement with values obtained by dialysis or ammonium sulfate precipitation. Several conditions should, however, be fulfilled: reliable methods for the determination of testosterone and SHBG, SHBG measurement in serum and not in plasma, use of fresh serum (not repeatedly frozen and thawed), absence of (exogenous) steroids competing for binding sites on SHBG and blood samples taken between 08.00 and 10.00 in the fasting state. Under these conditions an excellent correlation with dialysis and bioavailable testosterone (ammonium sulfate precipitation) is generally obtained.     

Osteoporosis in the aging population: the male perspective

The importance of senile osteoporosis in men as a public health problem has long been underestimated. Elderly men are at substantial risk for fracture, and morbidity after osteoporotic fractures appears to be more serious and mortality more common in men than in women. Risk factors for osteoporotic fractures in men appear to be qualitatively similar to those in women, but there are quantitative differences. Low bone mineral density (BMD) is an important risk factor for fracture in men; however, further clarification of the relationship between BMD, bone geometry and fracture risk is needed before formulating definitive proposals on operational densitometric criteria for diagnosis of osteoporosis in men and the identification of men at high risk for fracture. Understanding of the mechanisms underlying senile bone loss and the pathogenesis of senile osteoporosis in men remains fragmentary with, in particular, the need for further clarification regarding the precise impact of hormonal status in elderly men on skeletal homeostasis. Recommendations on prevention and treatment of senile osteoporosis in men should focus on the minimization of known risk factors for bone loss and falls. Testosterone treatment may be useful in those men with initially low serum testosterone. As to other pharmacological treatment modalities, prospective trials specifically in elderly men, and preferably with fracture incidence as the primary clinical endpoint, are required.     

Continence,incontinence and the aging male

This paper was presented at the Second International Workshop on the Aging Male, Weimar, Germany, November 1999     

Estradiol in elderly men

The role of estrogens in male physiology has become more evident, as a consequence of the discovery of human models of estrogen deficiency such as estrogen resistance or aromatase deficiency. In males, testosterone is the major source of plasma estradiol, the main biologically active estrogen, only 20% of which is secreted by the testes. Plasma estrone, 5% of which is converted to plasma estradiol, originates from tissue aromatization of, mainly adrenal, androstenedione. The plasma concentration of estradiol in males is 2-3 ng/dl and its production rate in blood is 25-40 μg/24 h; both of these values are significantly higher than in postmenopausal women. Plasma levels of estradiol do not necessarily reflect tissue-level activity as peripherally formed estradiol is partially metabolized in situ; thus, not all enters the general circulation, with a fraction remaining only locally active. Of the factors influencing plasma estradiol levels, plasma testosterone is a major determinant. However, the age-associated decrease in testosterone levels is scarcely reflected in plasma estradiol levels, as a result of increasing aromatase activity with age and the age-associated increase in fat mass. Free and bioavailable estradiol levels do decrease modestly with age as does the ratio of free testosterone to free estradiol, the latter testifying to the age-associated increasewd aromatization of testosterone. Estradiol levels are highly significantly positively related to body fat mass and more specifically to subcutaneous abdominal fat, but not to visceral (omental) fat. Indeed, aromatase activity in omental fat is only one-tenth of the activity in gluteal fat. Estrogens in males play an important role in the regulation of the gonadotropin feedback, several brain functions, bone maturation, regulation of bone resorption and in lipid metabolism. Moreover, they affect skin metabolism and are an important factor determining sex interest in man.     

Prevalence of sarcopenia and its association with functional and nutritional status among male residents in a nursing home in Turkey

Introduction The Aging Male Symptoms' (AMS) scale was designed as a health-related quality of life (QoL) scale and standardized as a self-administered scale, first, to assess symptoms of aging (independent from those which are disease-related) between groups of males under different conditions, second, to evaluate the severity of symptoms/QoL over time, and, third, to measure changes pre- and post-androgen replacement therapy. The scale is in widespread use (17 languages currently available) and a recent review of methodological data documented good psychometric characteristics and ability as a clinical utility. This paper describes test characteristics of the AMS (positive and negative predictive values), taking two internationally established and published screening scales for androgen deficiency as the available standard.

Method A sample of 150 German males aged 40–69 years completed the AMS scale and two screening scales for androgen deficiency: the ADAM scale of Morley and colleagues and the screener of Smith and colleagues. The technique of a computer-assisted telephone interview was applied.

Result The comparison of the AMS with the two screening instruments for androgen deficiency showed sufficiently good compatibility despite conceptual differences. The AMS scale sufficiently predicted the results of the two screening instruments. A positive predictive value of 92% and a negative predictive value of 50% were found regarding the ADAM scale. The respective figures regarding Smith's screener were 65% and 49% for positive and negative predictive values, respectively.

Conclusion The AMS scale obviously measures a similar phenomenon as the two established and widely used screeners for androgen deficiency, although it was not developed as a screening instrument.     

Increase in the prevalence of metabolic syndrome among workers according to age

Androgen levels decline over a man's lifetime. In a proportion of men (increasing with age), levels fall below values that have been established by conventional laboratory criteria as indicative of hypogonadism. Testosterone has a wide range of non-reproductive actions: it preserves bone and muscle mass, it acts on non-sexual mental functioning and it stimulates red blood cell formation. Long-term androgen deficiency has a great impact on quality of life. The first intervention studies provide indications that androgen treatment of men with true androgen deficiency is helpful. Obviously, only men who are testosterone-deficient will benefit from androgen supplementation. The diag nosis of testosterone deficiency in old age is not unambiguous. Signs and symptoms of aging sometimes clinically overlap with those of testosterone deficiency. The groups that are at higher risk of testosterone deficiency are those men with disease (pulmonary disease, gastrointestinal disease, rheumatoid disease, etc.). Usually, sex hormone binding globulin levels increase with aging, leading to lower levels of free, biologically available testosterone. For the time being, arbitrary criteria for testosterone deficiency in aging men have to be adopted. The best practical approach is to calculate the free testosterone level. The calculation can be found at www.issam.ch under 'Tools'.     

Preventing diseases of the prostate in the elderly using hormones and nutriceuticals

The prostate has only one function, namely to secrete fluid containing substances that are needed for reproduction. This requires an extremely high concentration of androgens in the tissues. Benign prostatic hypertrophy (BPH) seems to be related to the long-term exposure of the prostate to the strong androgen 5α-dihydrotestosterone (DHT) and, possibly, to estrogens. The relation between prostate cancer and androgens is suggested to be U-shaped, with both extremes of androgen concentrations being associated with increased risk of invasive cancer.

In the treatment of patients with BPH, the lipidic liposterolic extracts of Serenoa repens were as effective as the pharmaceutical inhibitors of the 5α-reductase enzyme or α₁-adrenergic blockers in relieving urinary symptoms. In addition to moderately inhibiting the 5α-reductase activity, Serenoa seems to exert anti-inflammatory and complementary cellular actions with beneficial effects on the prostate. Unlike the pharmaceutical 5α-reductase inhibitors, finasteride and dutasteride, Serenoa does not suppress serum PSA, facilitating the follow-up and the early detection of prostate cancer.

We suggest a strategy to prevent prostate cancer that aims at providing men with partial androgen deficiency correct testosterone substitution with a sustained release buccal bio-adhesive tablet. In addition, food supplementation with extracts of Serenoa repens and a combination of the antioxidants selenium, (cis)-lycopene and natural vitamin E, together with fish oil rich in long-chain polyunsaturated essential fatty acids of the omega-3 group seems warranted. Clearly, a holistic approach including careful clinical and biological monitoring of the aging man and his prostate remains mandatory.     

Performance of Massachusetts Male Aging Study (MMAS) and androgen deficiency in the aging male (ADAM) questionnaires in the prediction of free testosterone in patients aged 40 years or older treated in outpatient regimen

Abstract

Objective: At present, calculated free testosterone assessment is considered as the gold standard in diagnosing male hypogonadism. However, this assessment is not available for all the individuals diagnosed with decreased testicular function. The investigators of this study were, thus, prompted to evaluate whether the androgen deficiency in the aging male (ADAM) and the Massachusetts Male Ageing Study (MMAS) questionnaires could be used to replace biochemical parameters in the diagnosis for hypogonadism in men aged 40 years and above.

Methods: We evaluated 460 men, aged 40 years and above, all volunteers of a screening program for prostate cancer based at the Hospital de Clínicas of Porto Alegre. In this study, we assessed the efficiency of the ADAM and MMAS questionnaires in diagnosing Brazilian men with low levels of total, calculated free and bioavailable testosterone.

Results: The sensitivity of the ADAM questionnaire in diagnosing the calculated free testosterone was 73.6%, whereas specificity was 31.9%. ADAM could be used to properly classify our cohort into normal or hypogonadal individuals in 52.75% of the cases. The sensitivity of the MMAS questionnaire was 59.9%, whereas the specificity was 42.9%, resulting in a successful classification of 51.4% of the patients.

Conclusion: The ADAM and MMAS questionnaires showed adequate sensitivity in diagnosing male patients with low levels of free testosterone. However, because of the lack of specificity, these tools cannot replace calculated free testosterone assessments in men aged 40 years and above.     

Testosterone deficiency and the metabolic syndrome

Evidence is presented to link components of the metabolic syndrome to testosterone deficiency and obesity. Testosterone deficiency in hypogonadism or testosterone deprivation in normo-gonadotropic men increases fat mass as well as fasting insulin levels. Testosterone supplementation (TS) in a dose dependent manner, increase lean body mass (LBM), reduces fat mass, body mass index (BMI) and waist hip ratio in both young and elderly hypogonadal men. A negative association between T and insulin resistance as well as impaired glucose intolerance has been demonstrated and in type 2 diabetic men TS improves metabolic parameters. TS improves most components of the metabolic syndrome and also reduces inflammatory cytokines.     

Association between testosterone levels and the metabolic syndrome in adult men

Abstract

Objective: To evaluate the relationship between testosterone levels and the metabolic syndrome (MS) in men older than 45 years.

Methods: Six hundred and sixty men (45–70 years) selected from 2906 participants of a population screening for prostate cancer were included in this study. Testosterone and the components of MS were assessed in all men. MS was diagnosed according to NCEP-ATP III criteria. Triglycerides (TG)/HDL-cholesterol (chol) index was calculated.

Results: The presence of MS was inversely associated with testosterone (χ², p?<?0.001), independently of age (OR 0.802, CI 95%: 0.724–0.887, p?<?0.0001). Hypertension was the most frequent abnormality observed followed by elevated TG and waist circumference (WC). Testosterone correlated positively with HDL-chol (r: 0.14, p?<?0.0001) and negatively with body mass index (BMI)(r: ?0.29, p?<?0.0001), WC (r: ?0.26, p?<?0.0001), TG (r: ?0.20, p?<?0.0001), TG/HDL-chol (r: ?0.20, p?<?0.0001), glucose (r: ?0.11, p?=?0.005) and MS score (r: ?0.23, p?<?0.0001).

Conclusions: Our results show that in men older than 45 years, as long as testosterone levels decline, the prevalence of MS increases, independently of age. The correlations found between testosterone and four of the five components of MS, as well as with BMI and TG/HDL-chol ratio, a surrogate marker of insulin resistance, suggest considering male hypogonadism as a determinant of developmental abnormalities typical of MS.     

Bone mineral density in men with and without the metabolic syndrome

The objective of this study was to measure bone mineral density (BMD) in middle-aged men with and without the metabolic syndrome according to the International diabetes federation (IDF) definition from 2005. We studied 80 men (mean age: 51.9 ± 9.0 y, mean body mass index (BMI): 32.0 ± 1.7 kg/m²) with and 92 men without the metabolic syndrome (mean age: 52.6 ± 15.1 y, mean BMI: 24.9 ± 2.8 kg/m²). Height (cm), weight (kg), waist circumference (cm) and blood pressure were measured. Fasting plasma glucose (FPG) and blood lipids were determined. BMD at the lumbar spine and total hip was measured by dual X-ray absorptiometry on a Hologic QDR 4500 bone densitometer. In men around 59.3% had a waist circumference > 94 cm (abdominal obesity). Among them 58.7% showed abnormal BP values. Around 30.7% had FPG ≥ 5.6 mmol/L and 22.7% had low high density lipoprotein (HDL)-cholesterol and 36.6% had hypertriglyceridemia. In men with the metabolic syndrome, mean lumbar spine BMD was 0.986 ± 0.210 g/cm² and total hip BMD – 1.012 ± 0.209 g/cm². The corresponding values in men without this syndrome were 0.934 ± 0.179 g/cm² and 0.894 ± 0.189 g/cm², respectively. The inter-group BMD difference reached statistical significance only at the hip (p = 0.039). Respectively, the prevalence of osteoporosis at the central sites was significantly higher in men without the metabolic syndrome (MS) (13.2 versus 20.8%, p = 0.03). Our data confirmed the trend for higher BMD in the studied men with the metabolic syndrome.     

Imagined communities in the global game: soccer and the development of Dutch national identity

Abstract Using the recent history of Dutch soccer as an illustrative case, this article supports a line of argument in globalization studies that generally focuses on the variable reverberations of globalization and more specifically suggests that globalization entails the embattled redefinition of national identities. I show how the involvement of the Dutch national team in global competition aided the construction of a myth of national football distinction and how media coverage and discourse turned this myth into a key element of a re imagined national community. The Dutch view of themselves as a unique soccer nation fits familiar global patterns, and a sociologically informed critique of their romantic soccer self‐image displays the myth as myth. At the same time, however, the critique is part of the discourse, which involves more than an a historical expressive myth erected as a defence against globalization. I argue that it is more complex, more reflexive and more fluid than some accounts of soccer nationalism would lead us to expect or than nostalgic neopatriots might prefer. The article thus also offers a critique of a standard critique of national sports image‐making, which fits with a promising thrust in soccer and globalization scholarship.     

Prevalence of the metabolic syndrome and its relationship with diabetes mellitus by aging

Abstract

Introduction.?It is important to make a prompt diagnosis of metabolic syndrome (MetS) in order to prevent the development of cardio-/cerebro- vascular diseases and diabetes mellitus (DM). The authors estimated the risk of development of DM by the presence/absence of MetS and age groups.

Methods.?A cross-sectional study of subjects undergoing intensive health examination was conducted (3149 men aged 30–69 years). Diagnosis of MetS was based on the criteria of the National Cholesterol Education Program Expert Panel (NCEP).

Results.?The prevalence of DM occurring in association with MetS increased with age; it was 11.9% in subjects with MetS in their 30s, it was 19.8% in subjects with MetS in their 60s. The prevalence of DM among subjects who had one or two components of MetS also increased with age. There was a significant progressive increase of the odds ratio in subjects in their 30s, 40s, 50s and 60s who were judged as having MetS; significant increase of the odds ratio was seen in subjects in their 60s, even in those who were not judged as having MetS.

Conclusions.?Subjects with MetS show a high prevalence of DM, and the prevalence increased with age in the subjects.     

A cross-sectional study on the shift work and metabolic syndrome in Japanese male workers

Introduction.?Shift work has been reported to be associated with an increase in the metabolic syndrome (MetS). To clarify the association between the type of shift work and the risk of MetS, a cross-sectional field survey was conducted after adjusting for age and lifestyle factors.

Methods.?The subjects were 3007 Japanese males, aged 34–64 years old, who were employees (1700 day and 1307 shift workers) of a car-manufacturing company. The standard Japanese criteria for the diagnosis of MetS was used. Age, smoking habit, drinking habit, sleeping habit and exercise habit were used as the independent variables.

Results.?The prevalence of MetS in the day workers, two-shift workers, and three-shift workers were 13.8% (234/1700), 10.7% (120/1125) and 17.6% (32/182), respectively. There was a significant difference in the prevalence between the two-shift workers and the day workers. Estimation of the odds ratios (95% confidence intervals) of age, two-shift work and habitual exercise for MetS were 1.03 (1.01–1.04), 0.77 (0.61–0.98) and 0.64 (0.51–0.81), respectively.

Conclusion.?Two-shift work was associated with lower risk of MetS, which is not in accordance with past reports. This finding should therefore be re-analysed, including investigation of the job content in each group.