Mission Statement

Aim.?To investigate sex hormone and androgen receptor (AR) levels and to evaluate their relationship with diabetes mellitus (DM) in senile men.

Methods.?The cross-sectional study included 492 elderly men comprising 104 healthy subjects (mean age 71.4 ± 5.2 years), 259 subjects without DM (71.5 ± 5.0 years) and 129 DM patients (73.0 ± 6.3 years). Plasma concentrations of total testosterone (TT), free testosterone (FT), dehydroepiandrosterone sulphate, sex hormone-binding globulin (SHBG), estradiol (E₂), luteinising hormone) and follicle-stimulating hormone (FSH) were determined. AR-positive cells were measured by flow cytometry.

Results.?TT concentrations were significantly lower in the DM group (13.8 ± 4.7 nmol/l) than in the healthy (17.1 ± 6.1 nmol/l) and non-diabetes groups (15.8 ± 6.0 nmol/l; all P < 0.01). FT, SHBG, AR-positive proportion (AR%) and AR fluorescence intensity showed a decreasing trend among the healthy, non-DM and DM groups, but the differences were not significant. TT, E₂, E₂/testosterone and SHBG were negatively correlated with blood glucose. SHBG was positively correlated and TT and AR% were negatively correlated with the course of DM. Logistic multiple regression analysis revealed that age, waist/hip ratio, FSH, SHBG and AR% are potential risk factors for DM.

Conclusions.?Low levels of TT, SHBG and AR may be potential risk factors for DM in elderly men.     

The relationship between serum total testosterone and free testosterone levels with serum hemoglobin and hematocrit levels: a study in 1221 men

Objective: To investigate the relationship between serum total testosterone (TT) and free testosterone (FT) levels in men with anemia.

Methods: We reviewed the records of 1221 subjects between March 2009 and December 2014. All the subjects’ blood samples were drawn for TT and FT assays. Their serum hemoglobin (Hb) and serum hematocrit (Hct) levels were measured. The primary objective of our study was to investigate the association between TT and FT levels with Hb and Hct levels.

Results: The mean age was 59.82?±?12.71 years. The mean TT and FT levels were 4.54?±?2.02?ng/mL and 10.63?±?3.69?pg/mL, respectively. The mean Hb and Hct levels were 14.72?±?1.34?g/dL and 43.11?±?3.75%, respectively. Subjects with low TT (<2.35?ng/mL) had low Hb and Hct levels (p?p?Conclusions: Subjects with low TT and FT levels had low Hb and Hct levels. This suggests that TT and FT play a significant role in erythropoiesis. Testosterone replacement therapy may be effective in men with hypogonadism to reduce the incidence of anemia.     

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.     

Interleukin-18 and testosterone levels in men with metabolic syndrome

Objective: Interleukin 18 (IL-18) is an adipokine associated with obesity. Data about the relationship of IL-18 to the metabolic syndrome (MS) are still scarce. Low testosterone (T) levels are common in men with MS, but we did not find data about the levels of IL-18 in men with low T. The aim of this study was to determine the levels of IL-18 in men with MS with or without low T.

Patients and methods: A total of 251 men were included in the study. Of them 218 had MS (IDF 2005) and they were divided according to their morning total testosterone (TT) level (cutoff 10.4?nmol/l) into two groups: MS-low T (N?=?84) and MS-normal T (N?=?134). The control group consisted of 33 men without MS and low T. IL-18 was determined in serum using enzyme-linked immunosorbent assay. A small group of eight men with MS and low T levels received testosterone therapy for three months and physical and laboratory parameters were monitored at the end of that period.

Results: MS men were at mean age (±SD)?=?53.77?±?9.59 years; body mass index (BMI)?=?34.0?±?6.3?kg/m²; and TT?=?12.59?±?5.66?nmol/l. The control group was at age?=?52.12?±?5.2 years (NS); BMI?=?25.6?±?2.4?kg/m² (p?p?p?p?p?p?Conclusions: In this study, higher IL-18 levels were found in the presence of MS compared to healthy men, but they did not differ between men having MS with or without LOH.     

Testosterone is not associated with mortality in older African-American males

Introduction.?Although testosterone and its association with disease progression and mortality is a widely studied topic, no studies have evaluated mortality risks related to testosterone levels in an older African-American population. The mechanisms for known racial differences in mortality risk for certain cancers and cardiovascular risk factors are largely unknown. Elucidating a mortality risk associated with testosterone levels may give insight into the elevated risk for certain diseases in African-Americans.

Methods and results.?Study data were derived from a cohort 622 African-Americans (age 80.05?±?6.4, range 68–102) from Saint Louis, Missouri that includes 190 males (age 79.38?±?6.2, range 70–102). The eligible sample for this report includes 56 of the 190 males (age 78.89?±?6.9, range 70–102) who donated blood at baseline in 1992–1994 and subsequently tested for total testosterone and bioavailable testosterone. Covariates for adjusted analyses were lower body functional limitations, physician visits and comorbidities, also collected at baseline. Males' mean bioavailable testosterone levels (ng/dl) were 33.33?±?24.4 (n above 70?ng/dl?=?5) and mean total testosterone levels (ng/dl) were 246.63?±?118.7 (n above 300?ng/dl?=?20). Vital status was determined through 2002; 41 males (73%) were deceased and 15 were alive. Mortality did not differ among males with testosterone levels?<300 versus 300+ (p?=?0.42) or with bioavailable testosterone levels?<70 versus > 70 (p?=?0.34). Total testosterone levels did not predict mortality when adjusted for age (Adjusted Hazard Ratio [AHR]?=?0.998; 95% confidence interval [CI] 0.995–1.001; p?=?0.28) or adjusted for age and other covariates (AHR?=?0.099; 95% CI 0.996, 1.002; p?=?0.35). Bioavailable testosterone levels did not predict mortality when adjusted for age (AHR?=?0.992; 95% CI .977–1.007; p?=?0.30) or when adjusted for age and other covariates (AHR 0.991; 95% CI .976–1.006; p?=?0.261).

Conclusion.?In older African-American males, total and bioavailable testosterone levels, with and without adjustment for covariates, are not independently associated with mortality risk.     

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.     

Dutasteride improves bone mineral density in male patients with lower urinary tract symptoms and prostatic enlargement: a preliminary study

Introduction: We studied the effect of dutasteride on bone mineral density (BMD) in aging male patients with lower urinary tract symptoms (LUTS) and prostatic enlargement.

Methods: We prospectively studied 17 patients with LUTS and prostatic enlargement. Before and 1 year after dutasteride (0.5?mg daily), we assessed International Prostate Symptom Score (IPSS), prostatic volume (PV), serum prostatic-specific antigen (PSA) and testosterone. BMD in the lumbar and femur was measured by DEXA method.

Results: Dutasteride significantly reduced PV (from 51?±?24 to 34?±?17?ml, p?p?p?2, p?2, p?2, p?Conclusions: Dutasteride has a potential to improve BMD with elevation of serum testosterone in aging male patients with LUTS and prostatic enlargement.     

Total testosterone levels are correlated to metabolic syndrome components

Introduction: Metabolic syndrome (MetS) is a constellation of interrelated risk factors of metabolic origin. Some studies suggest a possible link between low total testosterone (TT) levels and the presence of MetS.

Aim: To analyze the strength and independence of associations between TT and MetS components in non-diabetic men.

Methods: In this cross-sectional study, 143 non-diabetic men older than 40 were analyzed.

Main outcomes measure: Blood samples were collected to evaluate metabolic profile and TT levels. MetS was defined as the presence of three or more of the following characteristics: fasting blood glucose levels?≥?100?mg/dL, triglyceride?≥?150?mg/dL, HDL-c??102?cm.

Results: Mean age of the study population was 61.5?±?8.61 years old. MetS was present in 47.9% of the individuals. Thirty-four men had low TT and MetS was observed in 23 (70%) against 50 (46%) in those with normal TT (≥?300?ng/dL) (OR 4.94, p?p?=?0.03) and HDL-c (Beta: 0.19; p?=?0.04) remained significantly correlated with TT levels.

Conclusions: Low TT levels were associated with MetS diagnosis. Abdominal obesity was the MetS component independently correlated to low TT levels.     

Effects of testosterone replacement therapy on hypogonadal men with osteopenia or osteoporosis: a subanalysis of a prospective randomized controlled study in Japan (EARTH study)

Objective: We investigated the effects of testosterone replacement therapy (TRT) on bone mineral density (BMD) among hypogonadal men with osteopenia/osteoporosis.

Methods: From our previous EARTH study population, 74 patients with a clinical diagnosis of osteopenia or osteoporosis and hypogonadism were included in this study, as the TRT (n?=?35) and control (n?=?34) groups. The TRT group was administered 250?mg of testosterone enanthate injection every 4 weeks for 12 months. The BMD, waist circumference, body mass index, body fat percentage, and muscle volume were measured at baseline and at 12 months. Blood biochemical data, including total cholesterol, triglycerides, HDL-cholesterol, hemoglobin A1c, and adiponectin values were also evaluated.

Results: At the 12-month visit, BMD significantly increased in both groups. However, comparisons on changes of parameter values from baseline to the 12-month visit between the TRT and control groups were significantly different in BMD (5.0?±?5.0 vs. 3.0?±?3.2; p?=?.0434) and in adiponectin value (?0.90?±?3.33 vs. 0.10?±?2.04; p?=?.0192). There were no significant changes in other parameters.

Conclusions: TRT for 12 months could improve BMD with a decrease in adiponectin levels among hypogonadal men with osteopenia/osteoporosis.     

Effects of acute androstenedione supplementation on testosterone levels in older men

The purpose of the study was to examine the effects of acute androstenedione supplementation on hormone levels in older men at rest and during exercise. Men (n?=?11) between the ages of 58 and 69 were divided into an experimental (n?=?6; 62.33?±?2.57 y) and control (n?=?5; 60.2?±?1.02 y) groups. Each participant received an oral 300?mg dose of either androstenedione (experimental) or a cellulose placebo (control) for 7 d. Pre- and post-supplementation participants completed two separate, 20-min strength tasks consisting of leg extension and leg curls at different percentages of their 10-RM. Researchers collected blood samples pre-, during, and post-exercise. Blood samples were analyzed for testosterone, androstenedione, and estradiol levels. The researchers found a significant difference between pre- (4.36?±?56?ng/mL) and post- (5.51?±?0.35?ng/mL) testosterone levels, as well as pre- (0.88?±?0.20) and post- (7.46?±?1.25) androstenedione levels, but no significant differences between pre- and post-estradiol levels for either group. It appears that short-term androstenedione supplementation augmented acute testosterone responses to resistance exercise in older men. However, further study of this supplement is needed to determine any potential it may have in mitigating andropause.     

The impact of testosterone replacement therapy on glycemic control,vascular function,and components of the metabolic syndrome in obese hypogonadal men with type 2 diabetes

Objective: This study set out to assess effects of testosterone replacement therapy (TRT) on parameters of metabolic syndrome and vascular function in obese hypogonadal males with type 2 diabetes mellitus (DM2).

Study design: Fifty-five obese hypogonadal diabetic males on oral hypoglycemic treatment were enrolled into this one-year, double-blind, randomized, placebo-controlled clinical study. Group T (n?=?28) was treated with testosterone undecanoate (1000?mg i.m. every 10?weeks) while group P (n?=?27) received placebo.

Methods: Anthropometrical and vascular measurements – flow-mediated dilatation (FMD) and intima media thickness (IMT) – biochemical and hormonal blood sample analyses were performed at the start of the study and after one year. Derived parameters (BMI, HOMA-IR, calculated free testosterone (cFT) and bioavailable testosterone (BT)) were calculated.

Results: TRT resulted in reduction of HOMA-IR by 4.64?±?4.25 (p?p?p?=?.005).

Conclusion: TRT normalized serum testosterone levels, improved glycemic control and endothelial function while exerting no ill effects on the study population.     

Correlation between sex hormone levels and obesity in the elderly male

Objective: To investigate the levels of sex hormones and androgen receptor (AR) in elderly male patients and to explore a possible correlation with obesity. Methods: The cross-sectional study included 314 Elderly males (age ≥ 65 year). Of these subjects, 104 were healthy (age range 65–92 year; mean 71.38 ± 5.154 year), 74 were obese (65–87 year; 71.32 ± 4.74 year), and 111 were overweight (65–85 year; 71.43 ± 5.03 year). The following parameters were measured: total testosterone (TT), free testosterone, dehydroepiandrosterone sulfate, sex hormone-binding globulin (SHBG), estradiol (E2), luteinizing hormone, follicle-stimulating hormone and AR. Results: (i) The levels of TT and SHBG in the obesity group were significantly lower than those in non-obese subjects. (ii) Body mass index (BMI) negatively correlated with TT and SHBG. (iii) Multiple regression analysis revealed that TT (β: ?0.230; p = 0.045) and SHBG (β: ?0.163; p = 0.02) were statistically correlated with BMI. Conclusion: Testosterone levels in the obese population were significantly lower than in the non-obese population and there is a significant association between testosterone levels and the extent of obesity.     

The effect of testosterone treatment on prostate histology and apoptosis in men with late-onset hypogonadism

Objectives: To investigate the effect of testosterone replacement therapy (TRT) on prostate histology and apoptosis in men with late-onset hypogonadism (LOH).

Methods: The study included 25 men, having LOH with prostate-specific antigen (PSA) level of 4?ng/ml or less. All patients underwent transrectal ultrasound guided prostate biopsy at baseline, and received testosterone undecanoate treatment for 1 year. Prostate biopsy was repeated at the end of 1 year of testosterone therapy. In addition to clinical and biochemical parameters, prostate histology and apoptotic index (AI) were compared before and after the TRT.

Results: The mean serum total testosterone significantly increased from 178.04?±?51.92 to 496.28?±?103.73?ng/dl (p?=?0.001). No significant differences were observed in serum total and free PSA level, prostate volume and maximal urinary flow rate. There were also no significant differences in AI, stroma/epithelial cells ratio, Ki-67 positive cells and atrophy score of prostate tissue before and after the TRT.

Conclusions: This study demonstrated that TRT did not affect serum PSA level, prostate volume and maximal urinary flow rate. This study also suggests that TRT does not cause the risk for prostate cancer development, because of no significant differences in prostate histology after TRT.     

Endogenous testosterone and brachial artery endothelial function in middle-aged men with symptoms of late-onset hypogonadism

In aging men, serum endogenous testosterone is inversely associated with common carotid intima-media thickness (IMT) and directly with beneficial plasma lipid levels; however, the relationship to endothelial function is poorly characterized. We examined the association between serum testosterone and endothelium-dependent brachial artery flow-mediated dilatation (FMD) in middle-aged to elderly men. A group of 83 men aged 40–69 years (mean 55.9?±?7.5 [SD]) with andropausal symptoms were studied. We measured their serum lipids, testosterone, luteinizing hormone, mean carotid IMT and brachial artery FMD by high resolution B-mode ultrasound. Brachial FMD correlated inversely with vessel diameter (r?=??0.38, p?=?0.0004), alcohol consumption (r?=??0.22, p?=?0.047) and serum testosterone (r?=??0.27, p?=?0.01), but not with luteinizing hormone. In multivariate analysis, FMD was explained by testosterone (β?=??0.17, p?=?0.0226), high density lipoprotein cholesterol (β?=?4.17, p?=?0.0312) and vessel diameter (β?=??4.37, p?<?0.0001) when adjusted for age, body mass index, triglycerides, blood pressure, carotid IMT, smoking, alcohol consumption, cardiovascular diseases and use of lipid lowering medication (HMG-CoA reductase inhibitors). In middle-aged to elderly men, there is an inverse correlation between serum testosterone and brachial FMD. These data suggest that testosterone may have an adverse effect on systemic endothelial function.     

Circulating testosterone and estradiol,autonomic balance and baroreflex sensitivity in middle-aged and elderly men with heart failure

Abstract

Background: Heart failure (HF) is considered as a cardiogeriatric syndrome. Its fundamental pathophysiological feature is autonomic imbalance (and associated abnormalities within cardiovascular reflex control), but recent evidence suggests the involvement of deranged hormone metabolism. Both these neural and endocrine pathologies have serious clinical and prognostic consequences in patients with HF. We investigated the relations between autonomic status, baroreflex sensitivity (BRS) and hormone status in men with mild systolic HF.

Methods: We examined 46 men with stable systolic HF (age: 62?±?10 years, NYHA class I/II: 10/36 [22%/78%], ischemic aetiology: 72%, left ventricular ejection fraction: 32?±?8%). Serum hormone levels (i.e. total testosterone [TT], dehydroepiandrosterone sulphate [DHEAS], oestradiol [E2], insulin-like growth factor type 1 [IGF-1] and cortisol) were assessed using immunoassays. Estimated free testosterone (eFT) was estimated using the Vermeulen’s equation. Heart rate variability (HRV) was assessed in time and frequency domains, based on 10-min resting recordings. BRS was estimated using the sequence method (BRS-Seq) and the phenylephrine test (BRS-Phe).

Results: Deficiencies in circulating TT, eFT, DHEAS and IGF-1 (defined as a serum hormone ≤the 10th percentile calculated for the adequate age category in the cohort of healthy men) were found in respectively 13%, 30%, 55% and 93% of men with systolic HF. Serum SHBG ≥50?nmol/L and cortisol ≥700?nmol/L characterised, respectively 44% and 29% of men with HF. In multivariable models after the adjustment for clinical variables, the following relationships were found in examined men: DHEAS and SDNN (time domain of HRV defined as a standard deviation of average R–R intervals) (β?=?0.29, p?=?0.03); E2 and: HRV-LF (ms²) (β?=?0.37, p?=?0.01), HRV-HF (ms²) (β?=?0.44, p?=?0.02) and BRS-Phe (β?=?0.51, p?=?0.008); TT and: HRV-HF (%) (β?=?0.35, p?=?0.02), HRV-LF/HF ratio (β?=??0.35, p?=?0.02) and BRS-Seq (β?=?0.33, p?=?0.04).

Conclusions: The observed associations between reduced circulating androgens, oestrogens and lower HRV and depleted BRS, irrespectively of HF severity suggest the pathophysiological links between these two mechanisms. These results constitute the premises to investigate whether the pharmacological supplementation of depleted hormones would enable to restore the autonomic balance and improve the efficacy of reflex control within the cardiovascular system in men with systolic HF.     

Influence of testosterone substitution on glycemic control and endothelial markers in men with newly diagnosed functional hypogonadism and type 2 diabetes mellitus: a randomized controlled trial

Abstract

Effects of testosterone (T) on the cardiovascular system of men remain controversial. The impact of T-replacement therapy (TRT) in men with functional hypogonadism and type 2 diabetes mellitus (T2DM) has to be elucidated. This study included 80 men (mean age 51.5?±?6.3 years) with newly diagnosed T2DM (according to ADA criteria) and functional hypogonadism (according to EAU criteria). Randomization: Group1 (n?=?40): TRT using 1%-transdermal T-gel (50?mg/day), Group2 (n?=?40) no TRT (controls). Dietary treatment applied to both. Parameters at baseline/after 9?months: anthropometric parameters, lipids and indicators of carbohydrate metabolism (fasting glucose, insulin, HbA1c, HOMA-IR), markers of adipose tissue and EnD (leptin, resistin, p- and e-selectin, ICAM- 1, VCAM- 1 and CRP). ANCOVA for repeated measurements revealed TRT to cause a significant decrease in waist circumference (WC), HOMA-IR and HbA1c vs controls (p?<?.001, p?=?.002, p?=?.004, respectively). Leptin declined in subjects receiving TRT vs controls (p?=?.04). Concentrations of resistin, ICAM-1, p-selectin and CRP decreased significantly vs controls (all p?<?.001); no effects for e-selectin and VCAM-1. Advanced age attenuated effects, higher delta testosterone levels augmented effects. Decrement of WC was related to decreasing markers of adipose tissue secretion/EnD. TRT in men with functional hypogonadism and T2DM improved carbohydrate metabolism and markers of endothelial dysfunction.     

The influence of comorbidities on the aging males’ symptoms scale in patients with erectile dysfunction

Objectives: To investigate if certain common age-related comorbidities are related with a positive aging males’ symptoms (AMS) test outcome.

Methods: This was a multicentric, transversal, observational study carried out in a male population with erectile dysfunction. Comorbidities and testosterone levels were registered. The relationship between comorbidities, testosterone levels, and the AMS test outcomes was studied using the global score and the sub-scale score components.

Results: The study included 1112 patients. In the multivariate analysis the global score strongly correlated with TT?p?Conclusion: Although the AMS test is related to low levels of testosterone, it is also of some limited use for diagnosing hypogonadism because it has low specificity and is influenced by pathologies that are frequent during ageing.     

High-intensity interval training (HIIT) increases insulin-like growth factor-I (IGF-I) in sedentary aging men but not masters’ athletes: an observational study

Introduction: The aim of this investigation was to examine the impact high-intensity interval training (HIIT) on serum insulin-like growth factor-I (IGF-I) in active compared with sedentary aging men.

Methods: 22 lifetime sedentary (SED; 62?±?2 years) and 17 masters’ athletes (LEX; 60?±?5 years) were recruited to the study. As HIIT requires preconditioning exercise in sedentary cohorts, the study required three assessment phases; enrollment (phase A), following preconditioning exercise (phase B), and post-HIIT (phase C). Serum IGF-I was determined by electrochemiluminescent immunoassay.

Results: IGF-I was higher in LEX compared to SED at baseline (p?=?0.007, Cohen’s d?=?0.91), and phase B (p?=?0.083, Cohen’s d?=?0.59), with only a small difference at C (p?=?0.291, Cohen’s d?=?0.35). SED experienced a small increase in IGF-I following preconditioning from 13.1?±?4.7 to 14.2?±?6.0?μg·dl^?1 (p?=?0.376, Cohen’s d?=?0.22), followed by a larger increase post-HIIT (16.9?±?4.4?μg·dl^?1), which was significantly elevated compared with baseline (p?=?0.002, Cohen’s d?=?0.85), and post-preconditioning (p?=?0.005, Cohen’s d?=?0.51). LEX experienced a trivial changes in IGF-I from A to B (18.2?±?6.4 to 17.2?±?3.7?μg·dl^?1 [p?=?0.538, Cohen’s d?=?0.19]), and a small change post-HIIT (18.4?±?4.1?μg·dl^?1 [p?=?0.283, Cohen’s d?=?0.31]). Small increases were observed in fat-free mass in both groups following HIIT (p?d?=?0.32–0.45).

Conclusions: In conclusion, HIIT with preconditioning exercise abrogates the age associated difference in IGF-I between SED and LEX, and induces small improvements in fat-free mass in both SED and LEX.