Impact of metabolic syndrome on erectile dysfunction and lower urinary tract symptoms in benign prostatic hyperplasia patients

Introduction.?The aim of this study was to investigate the relationship among metabolic syndrome (MetS), erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) in patients with benign prostatic hyperplasia (BPH).

Methods.?Our study included 106 patients with BPH, 33 (31.1%) of whom had MetS. Blood pressures, waist circumferences, serum levels of fasting blood glucose, high density lipoprotein and triglyceride of patients were recorded. Erectile functions of the patients were evaluated by International Index of Erectile Function (IIEF). Patients were divided into two groups according to IIEF scores, namely ‘mild/no ED’ and ‘moderate/severe ED’. IIEF scores of ED groups were between 17 and 30 and 6–16 in turn. LUTS severities were assessed by International Prostate Symptom Score (IPSS) and classified as mild (IPSS 0–7), moderate (IPSS 8–19) and severe (IPSS 20–35).

Results.?There was a significant difference between ED groups concerning MetS presence (p?=?0.032). MetS presence was not found to be associated with the severity of LUTS (p?=?0.144). There was no correlation between ED groups regarding LUTS severity (p?=?0.303).

Conclusion.?Results of the present study showed a correlation between MetS presence and ED. In the light of our results, MetS seems to play an important role in the etiopathogenesis of ED in patients with BPH.     

Impact of metabolic status on the association of serum vitamin D with hypogonadism and lower urinary tract symptoms/benign prostatic hyperplasia

Objective: The objective of this study is to investigate the impact of metabolic status on associations of serum vitamin D with hypogonadism and lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH).

Patients and methods: A total of 612 men underwent physical examination, biochemical/hormonal blood testing, and transrectal prostate ultrasound. Moreover, the subjects filled out standard questionnaires for identification and grading of LUTS and hypogonadism symptoms. Parameters were statistically compared with independent t-tests and correlation analyses.

Results: Vitamin D levels positively correlated with total testosterone (TT) but not with prostate volume or International Prostate Symptom Score (IPSS). Patients with metabolic syndrome had significantly lower vitamin D levels, which were not correlated with TT, prostate volume, or IPSS. However, vitamin D was positively correlated with TT, and negatively correlated with prostate volume and quality-of-life IPSS in subjects without metabolic syndrome.

Conclusion: The clinical usefulness of vitamin D for treatment of hypogonadism or LUTS/BPH varies according to metabolic status.     

Administration of daily 5 mg tadalafil improves endothelial function in patients with benign prostatic hyperplasia

Introduction: Tadalafil is a promising phosphodiesterase (PDE) 5 inhibitor prescribed for erectile dysfunction (ED). Daily low dose (5?mg) of tadalafil has also been used for the treatment of male lower urinary tract symptoms (LUTS) associated with benign prostate hyperplasia (BPH). PDE5 inhibitors induce relaxation of smooth muscle cells in the urethra, prostate, bladder neck, and blood vessels. The aim of this study was to investigate the efficacy of tadalafil on vessels endothelial function, in patients with male LUTS symptoms associated with BPH.

Methods: The Institutional Review Board (IRB) approved this clinical study and informed consents had been obtained from 81 BPH patients.

The following male LUTS parameters: international prostate symptom score (IPSS), overactive bladder symptom score (OABSS), voiding volume, max and mean voiding flow on voiding flowmetry examination and post-voiding residual urine (RU) were compared at 0, 1, 3, 6, and 12 months after a daily dose of 5?mg tadalafil.

In addition, erectile function was evaluated by the sexual health inventory for men (SHIM) score and vessels endothelial function and peripheral neuropathy were assessed by the brachial-ankle pulse wave velocity (baPWV), ankle brachial index (ABI), and vibration perception threshold (VPT) at 0, 3, 6, and 12 months after treatment.

Results: The mean age of 81 patients was 66.4?±?11.4 years old. Their prostate size was 30.2?±?22.1?ml.

Male LUTS parameters including IPSS, OABSS, and RU showed significant improvement from 1 to 12 months after tadalafil administration. Max and mean voiding flow was significantly increased at 6 months after tadalafil treatment.

The SHIM score showed significant improvement after 3 months. Whilst, the results of baPWV also showed significant improvement from 3 to 12 months. ABI was also significantly improved at 6 months. However, there was no change in the VPT at any time point.

Conclusions: Tadalafil is effective for both male LUTS and ED. It is also shown that tadalafil improves baPWV, which we can conclude that higher vessels elasticity has been obtained. This major finding of this study shows that tadalafil has the potency to improve vessels endothelial dysfunction in patients with BPH.     

Are urge incontinence and aging risk factors of erectile dysfunction in patients with male lower urinary tract symptoms?

Introduction: Several studies have indicated that erectile dysfunction (ED) patients also suffer from lower urinary tract symptoms (LUTS). We investigated a group of men with LUTS and assessed their sexual function with the aim of being able to predict ED risk factors and introduce ED treatments earlier for this patient group.

Methods: International Prostate Symptom Score (IPSS), Overactive Bladder Symptoms Score (OABSS) and Sexual Health Inventory for Men (SHIM) score were obtained from 236 men with LUTS at their first out-patients visit. Clinical parameters such as body mass index, prostate volume, residual urine volume and prostate specific antigen were also evaluated. The relationship between the SHIM score and other clinical data was analyzed.

Results: According to the SHIM score, ED in men with LUTS was severe 15%, moderate 19%, moderate to mild 28%, mild 17%, normal 7% and data was incomplete in 14%. Based on the results of a multivariate analysis, aging (p?p?=?0.024) were significantly correlated to severe and moderate ED. Furthermore, among OAB symptoms score items, urge urinary incontinence was a risk factor for severe and moderate ED (p?=?0.005).

Conclusion: Aging and OAB (notably urinary urge incontinence) are risk factors for severe and moderate ED in men with LUTS.     

The impact of metabolic syndrome on serum total testosterone level in patients with erectile dysfunction

Abstract

Objectives: To determine the association between metabolic syndrome (MetS) and serum testosterone levels (TT) in patients with erectile dysfunction (ED).

Methods: This study included 280 ED patients above 40-years-of-age. Participants were divided into two groups according to 2005 criteria of International Diabetes Federation. The severity of ED was determined according to the International Index of Erectile Function-EF (IIEF-EF score; 0–10 severe ED, 11–25 mild to moderate ED). The severity of ED, serum TT levels and other MetS components were compared between the groups.

Results: The mean age of the patients was 55.7?±?8.2 years. One hundred eighteen patients (%42.1) had MetS. Sixty-eight patients with MetS (57.6%) and 71 patients without MetS (43.8%) had severe ED (p?=?0.031). A total of 46 (16.4%) patients had hypogonadism. Hypogonadism was seen more prevalent in patients with MetS (22.9% vs. 11.7%, p?=?0.013). Logistic regression analyses for ED risk factors demonstrated that abnormal FBG increased the relative risk of severe ED up to 10.7-fold (p?<?0.001) but not presence of hypogonadism (p?=?0.706).

Conclusion: Metabolic syndrome was seen in almost half of the patients with ED. ED was more severe among MetS patients. Hypogonadism alone is a not risk factor for severe ED.     

Androgen replacement therapy contributes to improving lower urinary tract symptoms in patients with hypogonadism and benign prostate hypertrophy: a randomised controlled study

Purpose.?We performed a randomised controlled study regarding the effects of androgen replacement therapy (ART) on lower urinary tract symptoms (LUTS) in hypogonadal men with benign prostate hypertrophy (BPH).

Methods.?Fifty-two patients with hypogonadism and BPH were randomly assigned to receive testosterone (ART group) as 250?mg of testosterone enanthate every 4 weeks or to the untreated control group. We compared International Prostate Symptom Score (IPSS), uroflowmetry data, post-voiding residual volume (PVR) and systemic muscle volume at baseline and 12 months after treatment.

Results.?Forty-six patients (ART group, n?=?23; control, n?=?23) were included in the analysis. At the 12-month visit, IPSS showed a significant decrease compared with baseline in the ART group (15.7?±?8.7 vs. 12.5?±?9.5; p?<?0.05). No significant changes were observed in the control group. The ART group also showed improvement in maximum flow rate and voided volume (p?<?0.05), whereas no significant improvements were observed in the controls. PVR showed no significant changes in either group. In addition, the ART group showed significant enhancement of mean muscle volume (p?<?0.05), whereas no significant changes were seen in the controls.

Conclusion.?ART improved LUTS in hypogonadal men with mild BPH.     

Use of thermobalancing therapy in ageing male with benign prostatic hyperplasia with a focus on etiology and pathophysiology

Introduction: We investigated if “thermobalancing” therapy (TT), using Dr Allen’s therapeutic device (DATD) in men with benign prostatic hyperplasia (BPH), can aid in understanding the etiology and pathophysiology of BPH.

Methods: We compared urinary and other parameters of BPH patients who received TT over 6 months (treatment group) with those of healthy volunteers who had not received the treatment (control group). Dynamics of symptoms and indicators in each group were evaluated in comparison with their data at the beginning and end of the study. Parameters were the International Prostate Symptom Score (IPSS) for urinary symptoms and quality of life (QoL), ultrasound measurement of prostate volume (PV) and uroflowmetry (maximum flow rate, Q_max). TT effectiveness was examined in 124 men with BPH and PV?<60?mL. We also investigated the data of five patients with BPH and PV?>60?mL.

Results: TT decreased urinary symptoms and PV, increased Q_max and improved QoL in men with BPH, PV?<60?mL, and in men with BPH, PV?>60?mL.

Conclusions: The present study demonstrated that TT is effective for BPH, suggesting that blood circulation plays a crucial role in its cause. The continuous heat exposure that does not exceed the normal body temperature terminates the trigger of BPH development, “micro-focus” of hypothermia, and the following spontaneous expansion of capillaries. TT could be considered to be a useful tool in BPH treatment.     

The impact of irritative lower urinary tract symptoms on erectile dysfunction in aging Taiwanese males

Objective.?This study assessed the possible associations between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) in aging Taiwanese males and investigated the impact of various aspects of LUTS on ED.

Methods.?A free health screening for aging males (≥40 years old) was conducted in Kaohsiung Medical University Hospital. All the subjects had completed clinical data and answered questionnaires. ED and LUTS were assessed by validated symptom scales: the International Index of Erectile Function-5 (IIEF-5) and the International Prostate Symptom Score (IPSS).

Results.?A total of 339 eligible patients enrolled in this study with a mean age of 60.1 years old. In multiple logistic regression analysis, age and IPSS (p?<?0.001 and p?=?0.013, respectively) were significantly associated with ED after controlling other comorbidities. In a further age-adjusted multiple regression analysis, our results showed that irritative symptoms (p?=?0.042) have a more significant association with ED than the obstructive symptoms (p?=?0.101).

Conclusions.?Our results indicate that age and LUTS are the two most independent risk factors for ED. Aging Taiwanese males with LUTS are at increasing risk for ED, especially for those with significant irritative symptoms.     

Effects of dutasteride on lower urinary tract symptoms: a prospective analysis based on changes in testosterone/dihydrotestosterone levels and total prostatic volume reduction

This study analyzed the effects of dutasteride on lower urinary tract symptoms based on the association between changes in the total testosterone (TT)/dihydrotestosterone (DHT) levels and total prostate volume (TPV) reduction. Sixty participants diagnosed with benign prostatic hyperplasia were given 0.5?mg of dutasteride daily for 52 weeks. Measures of TT and DHT levels, TPV and uroflowmetry were obtained before and after dutasteride treatment. Forty-three patients demonstrated a TPV reduction of ≥5% (Group 1), whereas the remaining 17 patients demonstrated a TPV reduction of <5% (Group 2). DHT suppression and DHT/TT ratio at baseline were significantly higher in Group 1 than Group 2. International Prostate Symptom Scores (IPSS) and uroflowmetry were significantly improved in both groups. In Group 2, nine patients demonstrated some improvement in IPSS (Group 2A), whereas eight did not (Group 2B). The rate of TT increase and improvement in voiding symptoms were significantly higher in Group 2A than Group 2B. Dutasteride-induced TPV reduction is dependent on individual 5-α reductase inhibitor activity. Some patients demonstrating smaller dutasteride-induced TPV reduction may experience an improvement in voiding symptoms owing to an increased level of testosterone.     

The association between triglyceride high density lipoprotein cholesterol ratio and benign prostate hyperplasia in non-diabetic patients:a cross-sectional study

Objectives: To assess the association between triglyceride (TG)/high density lipoprotein (HDL) ratio and benign prostate hyperplasia/lower urinary tract symptoms (BPH/LUTS).

Methods: Four hundred patients who were admitted to the Urology Clinic between January and December 2014 with complaints of BPH/LUTS were enrolled in this cross-sectional study. Patients were divided into two groups according to their International Prostate Symptom Score and prostate volume (PV). They were compared in terms of age, body mass index (BMI), PV, PSA, post micturional residual volume, uroflowmetry Q max value, fasting blood sugar, TG and high density lipoprotein-cholesterol (HDL-C) level and TG/HDL ratio.

Results: Although univariate analyses reveal that age, BMI, waist circumference (WC), FBS, TG, HDL-C level, and TG/HDL ratio were correlated with PV, only age [1.125 OR (1.088–1.164), p?=?.00001], BMI [1.119 OR (1.040–1.204), p?=?.003], TG [(1.043 OR (1.016–1.071), p?=?.002], HDL-C [(0.923 OR (0.860–0.990), p?=?.025], and TG/HDL ratio [(1.224 OR (1.130–1.315), p?=?.014] were statistically significant in multivariate analysis. The calculated area under the curve (AUC) for PV of 30?ml, 40?ml, and 50?ml was 0.668 (0.608–0.727), 0.617 (0.561–0.673), and 0.592 (0.530–0.654), respectively.

Conclusions: Our results indicate that the TG/HDL ratio correlates with enhancement in PV. Further studies are warranted to better evaluate this relationship.     

Transurethral resection of the prostate achieves favorable outcomes in stroke patients with symptomatic benign prostate hyperplasia

Objectives: To evaluate the surgical outcomes of stroke patients with symptomatic benign prostatic hyperplasia (BPH) who underwent transurethral resection of the prostate (TURP) and compare the clinical outcomes between patients with stroke and those without stroke receiving this procedure.

Methods: This retrospective cohort study analyzed claims data collected during the period of 1997–2012 from Taiwan National Health Insurance Research Database. We enrolled 6625 patients who had persistent lower urinary tract symptoms and underwent TURP for BPH. They were categorized into a stroke (n?=?577) and nonstroke (n?=?6048) group. Patient characteristics, postoperative clinical outcomes, medication records, and medical expenses were compared.

Results: Compared with the stroke group patients, those in the nonstroke group were younger, had fewer comorbidities, and more favorable postoperative clinical outcomes. Nevertheless, TURP achieved favorable outcomes in stroke patients with symptomatic BPH. In the stroke group, the rate of urinary tract infection (UTI) decreased from 34.7% during 1 year preoperatively to 29.8% during 1 year postoperatively (p?=?.05). The rate of urinary retention (UR) also decreased from 55.5% during 1 year preoperatively to 22.5% during 1 year postoperatively (p?=?.05). TURP reduced the overall medical expenses of patients with stroke. Annual patient medical expense during 1 year preoperatively, 1 year postoperatively, 2 years postoperatively, and 3 years postoperatively was NT$659,000, NT$646,000, NT$560,000, and NT$599,000, respectively.

Conclusions: In patients with stroke, TURP reduces the risks of UTI and UR and annual total medical expense.     

Can the UroLift prostatic implant device treat the symptoms of benign prostatic hypertrophy,avoid sexual dysfunction and reduce hospital TURP waiting times? A single centre,single surgeon experience and review of the literature

BPH associated with LUTS and sexual dysfunction is common. We performed UroLift on 11 patients, average age 71?years (range 56–90). IPSS improved by an average of 9 points post-procedure. Pre-operatively their post-void residuals were 306.3?ml (range 120–499?ml SD [120.6]) and their Q_MAX was 7?ml/s (range 4–14 SD [2.8] ml/s). Post-procedure the post-void residual decreased by 35.4% at 4?months (mean difference – 106.3?ml). Q_MAX improved by an average of 1.7?ml/s, which was not statistically significant. No patients suffered any sexual dysfunction side effects and all patients were satisfied with their result. Hospital stay and theatre time were significantly reduced. Average length of stay was just 10.6 (6–18) hours and average theatre time just 18.7 (12–30) min. This is significantly faster than other surgery for LUTS. We therefore feel that there are significant benefits for both the patients, who are able to go home much faster, and also the hospital, who are able to perform far more surgeries for their patients. Patients also do not require an inpatient bed so patients should not be cancelled on the day of theatre.     

Prevalence of low testosterone and its relationship to body mass index in older men with lower urinary tract symptoms associated with benign prostatic hyperplasia

Abstract

Purpose: We examined the prevalence of low testosterone (LT) and its relationship with body mass index (BMI) in men with lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH), who were enrolled in a clinical trial of drug therapy, the Medical Therapy of Prostatic Symptoms (MTOPS) Study.

Materials and methods: MTOPS enrolled 3047 men, and of these, 1896 had total testosterone (TT) measured at baseline. LT was defined as a single measurement of TT of <300?ng/dL.

Results: The overall prevalence of LT was 25.7%. Prevalence increased with increasing BMI; 14.7% among men who were normal weight (BMI <25?kg/m²) and 24.2% and 39.3% among overweight (BMI 25 to <30?kg/m²), and obese (baseline BMI ≥30?kg/m²) men, respectively.

Conclusions: LT was observed in about one in four MTOPS study participants with baseline TT measurements. The prevalence of LT increased markedly with increasing BMI. Our findings suggest a high prevalence of LT in obese men with LUTS/BPH. Physicians should be alert to the possibility of symptoms of hypogonadism in this population.     

Patient-perceived effectiveness and impact on quality of life of solifenacin in combination with an α-blocker in men with overactive bladder in Sweden: a non-interventional study

Treating male lower urinary tract symptoms (LUTS) by targeting the prostate would have limited effect on overactive bladder (OAB) symptoms. This study assessed perceived symptoms and quality of life (QoL) of male patients with OAB treated with an α-blocker plus solifenacin in daily clinical practice. Male patients aged ≥40 years were included after the decision was made to initiate treatment with an α-blocker for LUTS plus solifenacin for OAB symptoms. The primary endpoint was change in patient perception of bladder condition (PPBC) questionnaire score over 6?months. Other assessments included the OAB-questionnaire short form (OAB-q SF) and International Prostate Symptom Score (IPSS). Interpretation of the study data was hindered by not meeting the enrollment target and a high dropout rate. In 36 evaluable patients, mean (SD) PPBC score improved from 4.3 (0.93) at baseline (“moderate” to “severe” problems) to 3.5 (1.06) at month 6 (“minor” to “moderate” problems). OAB-q SF scores and total IPSS also improved. In this patient population, treatment with solifenacin and an α-blocker resulted in improvements in male patient perception of their LUTS and QoL, although the results should be interpreted with caution due to the low number of patients with complete data.     

Effects of testosterone replacement therapy withdrawal and re-treatment in hypogonadal elderly men upon obesity,voiding function and prostate safety parameters

Whether testosterone replacement therapy (TRT) is a lifelong treatment for men with hypogonadism remains unknown. We investigated long-term TRT and TRT withdrawal on obesity and prostate-related parameters. Two hundred and sixty-two hypogonadal patients (mean age 59.5) received testosterone undecanoate in 12-week intervals for a maximum of 11 years. One hundred and forty-seven men had TRT interrupted for a mean of 16.9 months and resumed thereafter (Group A). The remaining 115 patients were treated continuously (Group B). Prostate volume, prostate-specific antigen (PSA), residual voiding volume, bladder wall thickness, C-reactive protein (CRP), aging male symptoms (AMS), International Index of erectile function – erectile function (IIEF-EF) and International Prostate Symptoms Scores (IPSS) were measured over the study period with anthropometric parameters of obesity, including weight, body mass index (BMI) and waist circumference. Prior to interruption, TRT resulted in improvements in residual voiding volume, bladder wall thickness, CRP, AMS, IIEF-EF, IPSS and obesity parameters while PSA and prostate volume increased. TRT interruption reduced total testosterone to hypogonadal levels in Group A and resulted in worsening of obesity parameters, AMS, IPSS, residual voiding volume and bladder wall thickness, IIEF-EF and PSA while CRP and prostate volume were unchanged until treatment resumed whereby these effects were reversed. TRT interruption results in worsening of symptoms. Hypogonadism may require lifelong TRT.     

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.     

Weapons of penile smooth muscle destruction: Androgen deficiency promotes accumulation of adipocytes in the corpus cavernosum

In men with erectile dysfunction, venous leakage is a common condition among non-responders to medical management and is attributed to penile smooth muscle atrophy. Androgens play a role in regulating trabecular smooth muscle growth and function. Further, androgens stimulate differentiation of progenitor cells into smooth muscle cells and inhibit their differentiation into adipocytes. We postulate that androgens exert a direct effect on penile tissue to maintain erectile function, and that androgen deficiency produces metabolic and structural imbalances in the corpus cavernosum, resulting in venous leakage and erectile dysfunction. To date, research efforts on the mechanisms by which androgens regulate penile erectile physiology have mainly focused on investigating the role of the NO/cGMP pathway. However, androgen-dependent mechanisms that regulate tissue remodeling have been poorly defined. Characterization of the molecular and cellular mechanisms by which androgens regulate corpus cavernosum structural and functional integrity would provide significant gains in knowledge and understanding of an important pathogenic process. In this review, we discuss the potential role of androgen in maintaining differentiation of progenitor cells into smooth muscle lineage and inhibition of differentiation into adipocytes. Androgen deficiency promotes differentiation into adipogenic lineage, and accumulation of adipocytes in the corpus cavernosum may contribute to erectile dysfunction.     

Daily use of sildenafil 50mg at night effectively ameliorates nocturia in patients with lower urinary tract symptoms associated with benign prostatic hyperplasia: an exploratory multicenter,double-blind,randomized, placebo-controlled study

Purpose: To compare the efficacy and safety of sildenafil 25?mg qd, 25?mg bid or 50?mg qd – on treating lower urinary tract symptoms with benign prostatic hyperplasia (LUTS/BPH).

Materials and methods: Men aged?>?45 years with LUTS/BPH were randomly assigned to receive sildenafil 25?mg qd (n?=?42), bid (n?=?41), 50?mg qd (n?=?38) or placebo (n?=?41) for 8 weeks. Changes from baseline in International Prostate Symptom Score (I-PSS), maximum urinary flow rate (Qmax) and postvoid residual urine volume (PVR) were assessed at week 4 and week 8.

Results: Sildenafil 25?mg qd (-7.3?±?5.8) and 25?mg bid (-7.0?±?5.7) exhibited significant improvements of I-PSS compared to placebo (-5.2?±?6.4) (p?=?0.020, 0.025, respectively). In particular, voiding domain was more affected than storage domain. Only sildenafil 50?mg qd improved nocturia significantly (versus placebo, p?=?0.027). Quality of life score was improved in all treatment groups. Q_max and PVR did not change significantly in all groups. All regimens were well tolerated.

Conclusions: Sildenafil 25?mg qd, 25?mg bid and 50?mg qd are safe and effective to improve LUTS/BPH in long term, along with coexisting ED. In particular, nocturia is most well-controlled by 50?mg qd.     

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.