Assessment of hypogonadism and its determinants among adult men with type 2 diabetes mellitus.

BACKGROUND AND AIMS: The impact of utilizing both symptoms as well as biochemically confirmed androgen deficiency in diagnosis of hypogonadism among type 2 diabetic men is relatively less studied. Furthermore, various determinants of hypogonadism in these men especially the role of insulin resistance and hypogonadism were studied. METHODS: This is a cross sectional study of 353 T2DM men aged 20-70 years of age. Hypogonadism was defined by taking both symptoms as well as calculated testosterone levels. Symptoms were defined using androgen deficiency in ageing male (ADAM) criteria. Various metabolic and clinical parameters were assessed and evaluated with regards to presence or absence of hypogonadism. RESULTS: Among 353 patients, 60 had both symptoms as well as biochemical evidence of hypogonadism. Assessment of calculated free testosterone but not total testosterone identified all such patients. Body mass index, HbA1c, fasting triglyceride level and HOMA IR inversely correlated with calculated free testosterone. We found that insulin resistance (HOMA IR) was independently associated with hypogonadism (odds ratio=1.108). CONCLUSION: Assessment of both symptoms of hypogonadism and calculated free testosterone represents a better way for correct identification of hypogonadal diabetic men. Insulin resistance has a strong association with hypogonadism independent of obesity and complication status of diabetes.

The importance of SHBG and calculated free testosterone for the diagnosis of symptomatic hypogonadism in HIV-infected men: a single-centre real-life experience.

PURPOSE: The prevalence of low testosterone and symptoms of hypogonadism in HIV-infected men is still debated. We aimed to estimate the prevalence and type of hypogonadism in HIV-infected males complaining about sexual symptoms, and to evaluate the role of calculated free testosterone (cFT) vs total testosterone (TT) for diagnosis. Furthermore, we evaluated relationship between sex hormone-binding globulin (SHBG), gonadal status and clinical and virologic parameters. METHODS: We retrospectively evaluated 169 HIV-infected men with sexual symptoms, with TT available. Among them, we selected 94 patients with TT, SHBG, cFT, and luteinizing hormone (LH) available, and classified hypogonadism into overt (low TT and/or low cFT) and compensated (high LH, normal TT and cFT). Comparison was performed by non-parametric Kruskal-Wallis test and Spearman's correlation was calculated to verify the possible associations. RESULTS: Overt and compensated hypogonadism were found in 20.2% and 13.8% of patients, respectively. With reliance on TT alone, only 10.6% of patients would have met diagnosis. SHBG values were elevated in one third of patients, and higher in men with compensated hypogonadism. Significant positive correlation was found between SHBG and HIV infection duration, TT and LH. CONCLUSION: Only a complete hormonal profile can properly diagnose and classify hypogonadism in HIV-infected men complaining about sexual symptoms. TT alone reliance may lead to half of diagnoses missing, while lack of gonadotropin prevents the identification of compensated hypogonadism. This largely comes from high SHBG, which seems to play a central role in the pathogenesis of hypogonadism in this population.

Prevalence of late-onset hypogonadism among middle-aged and elderly males in China: results from a national survey.

This study aimed to propose an operational definition of late-onset hypogonadism (LOH) that incorporates both clinical symptoms and serum testosterone measurements to evaluate the prevalence of LOH in aging males in China. A population-based sample of 6296 men aged 40 years-79 years old was enrolled from six representative provinces in China. Serum total testosterone (TT), sex hormone-binding globulin (SHBG), and luteinizing hormone (LH) were measured and free testosterone (cFT) was calculated. The Aging Males' Symptoms (AMS) scale was used to evaluate the LOH symptoms. Finally, 5078 men were included in this analysis. The TT levels did not decrease with age (P = 0.59), and had no relationship with AMS symptoms (P = 0.87 for AMS total score, P = 0.74 for ≥ 3 sexual symptoms). The cFT levels decreased significantly with age (P < 0.01) and showed a negative association with the presence of ≥ 3 sexual symptoms (P = 0.03). The overall estimated prevalence of LOH was 7.8% (395/5078) if a cFT level <210 pmol l-1 combined with the presence of ≥ 3 sexual symptoms was used as the criterion of LOH. Among them, 26.1% (103/395) and 73.9% (292/395) had primary and secondary hypogonadism, respectively. After adjustment for confounding factors, primary and secondary hypogonadism was positively related to age and comorbidities. Body mass index was an independent risk factor for secondary hypogonadism. The results suggest that the AMS total score is not an appropriate indicator for decreased testosterone, and that the cFT level is more reliable than TT for LOH diagnosis. Secondary hypogonadism is the most common form of LOH.

Sociodemographic, lifestyle and medical influences on serum testosterone and sex hormone-binding globulin in men from UK Biobank.

OBJECTIVE: Serum testosterone concentrations are affected by factors unrelated to hypothalamo-pituitary-testicular axis pathology. We evaluated the impact of sociodemographic, lifestyle and medical factors, on serum testosterone and sex hormone-binding globulin (SHBG) in men aged 40-69 years. DESIGN: Cross-sectional analysis of 208,677 community-dwelling men from the UK Biobank. MEASUREMENTS: We analysed associations of different factors with serum testosterone and SHBG (immunoassays) and calculated free testosterone (cFT), using smoothed centile plots, linear mixed models and effect size estimates. RESULTS: Median (interquartile range) for serum testosterone was 11.6 (9.4-14.1) nmol/L, SHBG 36.9 (27.9-48.1) nmol/L and cFT 213 (178-255) pmol/L. Age and BMI were inversely associated with testosterone and cFT, while SHBG was associated with age and inversely with BMI (all P < .001). Living with a partner, (South) Asian ethnicity, never or previous smoker and some medical conditions were associated with lower testosterone. Poultry or fish eater, and higher physical activity were associated with higher testosterone (all P < .001). Testosterone was lowered by ~0.5 nmol/L across ages, ~1.5 nmol/L for BMI 30 vs 25 kg/m2 , ~2 nmol/L for (South) Asian ethnicity, living with partner, college/university qualifications, low red meat eater, insufficient physical activity and 0.3-1.0 nmol/L with cardiovascular disease or diabetes. Different combinations of these factors varied serum testosterone by ~4 nmol/L, SHBG by ~30 nmol/L and cFT by ~60 pmol/L. CONCLUSIONS: The identified modifiable risk factors support lifestyle-based interventions in men with low testosterone concentrations. Considering sociodemographic, lifestyle and medical factors facilitates more personalized interpretation of testosterone testing results with respect to existing reference ranges.

Prevalence of late-onset hypogonadism among middle-aged and elderly males in China: results from a national survey / 亚洲男科学杂志(英文版)

This study aimed to propose an operational definition of late-onset hypogonadism (LOH) that incorporates both clinical symptoms and serum testosterone measurements to evaluate the prevalence of LOH in aging males in China. A population-based sample of 6296 men aged 40 years-79 years old was enrolled from six representative provinces in China. Serum total testosterone (TT), sex hormone-binding globulin (SHBG), and luteinizing hormone (LH) were measured and free testosterone (cFT) was calculated. The Aging Males' Symptoms (AMS) scale was used to evaluate the LOH symptoms. Finally, 5078 men were included in this analysis. The TT levels did not decrease with age (P = 0.59), and had no relationship with AMS symptoms (P = 0.87 for AMS total score, P = 0.74 for ≥ 3 sexual symptoms). The cFT levels decreased significantly with age (P < 0.01) and showed a negative association with the presence of ≥ 3 sexual symptoms (P = 0.03). The overall estimated prevalence of LOH was 7.8% (395/5078) if a cFT level <210 pmol l

Assessment of free testosterone concentration.

Testosterone (T) is strongly bound to sex hormone binding globulin and measurement of free T may be more appropriate than measuring total serum T, according to the free hormone theory. This view remains controversial and it has its detractors who claim that little extra benefit is gained than simply measuring total T, but it is endorsed by recent clinical practice guidelines for investigation of androgen disorders in both men and women. Free T measurement is very challenging. The gold standard equilibrium dialysis methods are too complex for use in routine clinical laboratories, assays are not harmonized and consequently there are no common reference intervals to aid result interpretation. The algorithms derived for calculating free T are inaccurate because they were founded on faulty models of testosterone binding to SHBG, however they can still give clinically useful results. To negate the effects of differences in binding protein constants, some equations for free T have been derived from accurate measurement of testosterone in large population studies, however a criticism is that the equations may not hold true in different patient populations. The free androgen index is not recommended for use in men because of inaccuracy at extremes of SHBG concentration, and in women it can also give inaccurate results when SHBG concentrations are low. If the free hormone hypothesis is to be believed, then calculated free testosterone may offer the best way forward but better equations are needed to improve accuracy and these should be derived from detailed knowledge of testosterone binding to SHBG. There is still much work to be done to improve harmonization of T and SHBG assays between laboratories because these can have a profound effect on the equations used to calculate free testosterone.

The free androgen index is inaccurate in women when the SHBG concentration is low.

OBJECTIVE/CONTEXT: The free androgen index (FAI) is known to give erroneous results in men, but it is still a commonly used test for the investigation of hyperandrogenism in women. This study aimed to compare the results of the FAI with the gold standard equilibrium dialysis method for free testosterone in women. DESIGN/PATIENTS: Free serum testosterone T (ED-T) and total serum T (T) were measured by equilibrium dialysis and LC-MS/MS in patients with polycystic ovarian syndrome (n = 130), normal female controls (n = 53) and normal males (n = 120). Calculated free T (cFT) and free androgen index (FAI) were also measured in these patients. In addition, cFT was retrospectively calculated in 4223 female patients with a normal T (<1.6 nmol/L) routinely investigated for hyperandrogenism. RESULTS: The cFT showed good agreement with measured ED-T, and the ratio cFT/ED-T was stable across all SHBG concentrations. In contrast, the FAI/ED-T ratio and the FAI/cFT ratio increased when the concentration of SHBG fell below 30 nmol/L. CONCLUSIONS: The FAI is not a reliable indicator of free T when the SHBG concentration is low and would give misleading information in a large number of women being investigated for hyperandrogenism.

Does Calculated Free Testosterone Overcome Total Testosterone in Protecting From Sexual Symptom Impairment? Findings of a Cross-Sectional Study.

BACKGROUND: Although erectile dysfunction (ED) has been associated with low circulating total testosterone (TT) levels, the utility of free testosterone (FT) over TT is debatable. AIM: To assess the relative impact of low TT and low calculated FT (cFT) on androgen-related sexual symptoms in men with ED. METHODS: Data from 485 men were analyzed. Comorbidities were scored with the Charlson Comorbidity Index (CCI). Patients completed the International Index of Erectile Function (IIEF) and the Beck Inventory for Depression (BDI). Descriptive statistics tested differences between patients with normal TT levels (>3 ng/mL) and normal cFT levels (>65 pg/mL; group 1) and men with normal TT and low cFT (group 2), low TT and normal cFT (group 3), and low TT and low cFT (group 4). Linear regression models tested the association between clinical predictors and sexual function impairment. OUTCOMES: We assessed the impact of different hormonal categories on androgen-related symptoms and the clinical utility of measuring cFT in men with ED. RESULTS: Groups 1, 2, 3, and 4 were composed of 338 (69.6%), 44 (9.1%), 34 (7.0%), and 69 (14.3%) patients, respectively. Compared with group 1, patients in group 2 were older (P < .001), had a higher body mass index (P < .01), and had a larger proportion with CCI scores of at least 1 (P = .006). Likewise, group 2 presented lower scores for the IIEF erectile function (P = .07), sexual desire (P = .04), and orgasmic function (P = .007) domains and lower BDI scores (P = .02) than group 1. Similar findings were found for group 4 vs 1. Conversely, patients in group 3 had similar scores on the questionnaires to those in group 1. Low cFT and normal or low TT achieved independent predictor status for pathologic IIEF domains and BDI scores after accounting for age, CCI, and body mass index. Conversely, low TT and normal cFT status was not associated with pathologic scores on the questionnaires. CLINICAL IMPLICATIONS: The inclusion of cFT in the first-line assessment of hypogonadal symptoms in men with ED has major clinical utility. STRENGTHS AND LIMITATIONS: This is the first study evaluating the concomitant impact of TT and cFT on men with ED using well-validated instruments to assess patients' sexuality and depressive symptoms. Limitations are the retrospective nature of the study and lack of physical function data and bone ultrasound measurements. CONCLUSIONS: Although normal cFT was not associated with signs and symptoms suggestive of testosterone deficiency, even when concomitant with low TT or low cFT irrespective of TT values, it was indicative of poorer clinical profiles and impaired sexual and depressive parameters compared with normal TT and normal cFT in a cohort of patients with ED. Boeri L, Capogrosso P, Ventimiglia E, et al. Does Calculated Free Testosterone Overcome Total Testosterone in Protecting From Sexual Symptom Impairment? Findings of a Cross-Sectional Study. J Sex Med 2017;14:1549-1557.

Comparing calculated free testosterone with total testosterone for screening and diagnosing late-onset hypogonadism in aged males: A cross-sectional study.

OBJECTIVE: The aim of this study is to compare calculated free testosterone (cFT) and total testosterone (T) in predicting late-onset hypogonadism (LOH) in middle-aged and elderly males. METHODS: We surveyed a random sample of 608 males between the ages of 45 and 87 years from Shanghai, China. The Aging Male Symptoms (AMS) questionnaire and the Androgen Deficiency in Aging Male (ADAM) questionnaire were completed by the subjects. Testosterone (T), sex hormone-binding globulin (SHBG), albumin, and other blood biochemical indexes were measured in 332 males. The corresponding cFT was obtained using the Vermeulen formula and the correlations between T and cFT were analyzed by SPSS statistical software. RESULTS: Among the 332 males who underwent biochemical evaluation, 289 males (87.0%) was positively screened by the ADAM questionnaire and 232 males (69.9%) by the AMS questionnaire. As suggested by linear regression, cFT exhibited a negative correlation with age in both ADAM+ and AMS+ group, whereas T did not appear to have significant correlation with age. Besides, there were statistically significant differences in cFT (P<.001) in the AMS questionnaire. CONCLUSIONS: Calculated free testosterone levels are more reliable than T levels for diagnosing LOH in middle-aged and elderly males.

[Diagnostic criteria for late-onset hypogonadism: A preliminary study].

OBJECTIVE: To determine the stability of androgen indexes by analyzing the relationship of androgen indexes with the results of late-onset hypogonadism (LOH) questionnaire investigations, and offer some reference for the application of the diagnostic criteria for LOH released by The Chinese Society of Andrology in 2009. METHODS: This study included 1 003 males aged 40 years or older who had accomplished the questionnaires of Androgen Deficiency in Aging Males (ADAM), Aging Males' Symptoms Scale (AMS), and International Index of Erectile Function-5 (IIEF-5). We evaluated the correlation of androgen indexes with the results of the questionnaire investigation, repeated the examination of androgen indexes for the subjects with total testosterone (TT) ≤11.5 nmol/L after an average of 1.5 years, and analyzed the factors inducing changes of androgen indexes. RESULTS: Free testosterone index (FTI) ≤ 0.42 (OR, 1.369) and calculated free testosterone (cFT) ≤ 0.3 nmol/L (OR, 1.302) were considered as the risk factors of LOH in AMS, and so were testosterone secretion index (TSI) ≤ 2.8 nmol/IU (OR, 1.679) and cFT ≤ 0.3 nmol/L (OR, 1.371) in IIEF-5. Paired t-test on the results of the examination performed twice showed significant differences in the levels of TT, TSI, cFT, and FT (P<0.05). CONCLUSIONS: Decreased testosterone may cause the diversity of LOH symptoms and hence the fluctuation of androgens. Therefore, the diagnosis of LOH depends on androgen indexes, varied symptoms in the questionnaires, and relief of the symptoms after testosterone therapy.

Diagnostic criteria for late-onset hypogonadism: A preliminary study / 中华男科学杂志

<p><b>Objective</b>To determine the stability of androgen indexes by analyzing the relationship of androgen indexes with the results of late-onset hypogonadism (LOH) questionnaire investigations, and offer some reference for the application of the diagnostic criteria for LOH released by The Chinese Society of Andrology in 2009.</p><p><b>METHODS</b>This study included 1 003 males aged 40 years or older who had accomplished the questionnaires of Androgen Deficiency in Aging Males (ADAM), Aging Males' Symptoms Scale (AMS), and International Index of Erectile Function-5 (IIEF-5). We evaluated the correlation of androgen indexes with the results of the questionnaire investigation, repeated the examination of androgen indexes for the subjects with total testosterone (TT) ≤11.5 nmol/L after an average of 1.5 years, and analyzed the factors inducing changes of androgen indexes.</p><p><b>RESULTS</b>Free testosterone index (FTI) ≤ 0.42 (OR, 1.369) and calculated free testosterone (cFT) ≤ 0.3 nmol/L (OR, 1.302) were considered as the risk factors of LOH in AMS, and so were testosterone secretion index (TSI) ≤ 2.8 nmol/IU (OR, 1.679) and cFT ≤ 0.3 nmol/L (OR, 1.371) in IIEF-5. Paired t-test on the results of the examination performed twice showed significant differences in the levels of TT, TSI, cFT, and FT (P<0.05).</p><p><b>CONCLUSIONS</b>Decreased testosterone may cause the diversity of LOH symptoms and hence the fluctuation of androgens. Therefore, the diagnosis of LOH depends on androgen indexes, varied symptoms in the questionnaires, and relief of the symptoms after testosterone therapy.</p>

Validity of serum testosterone, free androgen index, and calculated free testosterone in women with suspected hyperandrogenism.

OBJECTIVES: There are technical limitations for the currently available methods of measuring serum total and free testosterone in females. The study objectives were to evaluate the usefulness of serum total testosterone, sex hormone-binding globulin (SHBG), free androgen index (FAI), and calculated free testosterone (CFT) in the assessment of androgen status in women investigated for suspected hyperandrogenism. METHODS: This is a case control study that was conducted during the period from 1(st) May 2011 to 31(st) October 2011 on 122 patients aged (18-45 years) whom were referred to the Clinical Biochemistry Laboratory from the Endocrinology and Gynecology Clinics, Royal Hospital, Oman. Women with no clinical feature or laboratory data indicative of hormonal dysfunction and with midluteal progesterone >30 nmol/L were selected as controls (group 1; n=18). The patients were divided into subgroups based on the clinical/laboratory diagnosis of polycystic ovary syndrome (PCOS [group 2; n=19), hirsutism (group 3; n=18), menstrual disturbances (irregularities) or infertility (group 4; n=49), as well as combination of PCOS or hirsutism and menstrual disturbances or infertility (group 5; n=18). Serum total testosterone and SHBG were measured, FAI was calculated as percentage ratio of total testosterone to SHBG values, and CFT was calculated according to Vermeulen equation. RESULTS: There was a statistically significant difference in the mean levels of testosterone, FAI and CFT in each patient group compared with the control group. For diagnosing hyperandrogenism, each indicator was selected at the recommended cut-off: testosterone >3.0 nmol/L, SHBG <30 nmol/L, FAI >5%, and CFT >32 pmol/L. In group 2, 89.5% and 94.7% of the patients had increased FAI and CFT, respectively; compared with 36.4% for increased testosterone. In group 3, 88.9% and 88.9% of the patients had similarly increased FAI and CFT, respectively; compared with 66.7% for testosterone. In group 4, patients had 63.3% and 73.5% elevated FAI and CFT, respectively; compared with 53.1% for testosterone, while in group 5, patients had 83.3% and 88.9% elevated FAI and CFT, respectively, compared with 61.1% for testosterone. CONCLUSION: The diagnosis of hyperandrogenism was most obvious when using CFT or FAI than testosterone alone. It is thus recommended to include these calculated parameters (CFT and/or FAI) in the routine investigation and assessment of women with disorders related to clinical or biochemical hyperandrogenism.

Laboratory diagnosis of late-onset male hypogonadism andropause / Diagnóstico laboratorial do hipogonadismo masculino tardio (andropausa)

OBJECTIVES: To evaluate which factors influence the laboratorial diagnosis of late-onset male hypogonadism (LOH). METHODS: Total testosterone (TT), SHBG and albumin were measured in 216 men aged 52-84 years. The laboratorial definition of LOH was two values of calculated free testosterone (cFT) <6.5 ng/dl, according to Vermeulen's formula. RESULTS: At the first blood test, cFT was <6.5 ng/dl in 27 percent of the men. Laboratorial LOH (confirmed by two tests) was present in 19 percent, but TT levels were low in only 4.1 percent. Age influenced TT (p=0.0051) as well as BMI; 23.5 percent of patients > 70 years and 38.9 percent of the obese men who had TT within the reference range were, in fact, hypogonadal. CONCLUSION: Especially in obese men and in those > 70 years old, SHBG dosage is important to calculate FT levels and diagnose hypogonadism.

OBJETIVOS: Avaliar os fatores que influenciam o diagnóstico laboratorial do hipogonadismo masculino tardio. MÉTODOS: Avaliamos 216 homens entre 52 e 84 anos. O diagnóstico laboratorial foi definido como dois valores de testosterona livre calculada (TLC) <6,5 ng/dl, segundo a fórmula de Vermeulen, a partir das dosagens de testosterona total (TT), SHBG e albumina. RESULTADOS: Na primeira dosagem, a TLC foi <6.5 ng/dl em 27 por cento da amostra. Hipogonadismo laboratorial (confirmado por duas dosagens) esteve presente em 19 por cento, no entanto a TT foi baixa em apenas 4.1 por cento dos homens. A idade influenciou a TT (p=0.0051) bem como o IMC; 23,5 por cento dos homens > 70 anos e 38,9 por cento dos obesos com TT dentro dos níveis de referência eram, na verdade, hipogonádicos. CONCLUSÃO: Especialmente em homens obesos e nos > 70 anos a dosagem de SHBG é importante para calcular TL e diagnosticar o hipogonadismo.

Risk of erectile dysfunction induced by arsenic exposure through well water consumption in Taiwan.

BACKGROUND: Erectile dysfunction (ED) has a profound impact on the quality of life of many men. Many risk factors are associated with ED, such as aging, sex hormone levels, hypertension, cardiovascular diseases, and diabetes mellitus. Arsenic exposure could damage peripheral vessels and increase the risk of cardiovascular disease. However, the relationship between arsenic exposure and ED has seldom been evaluated. OBJECTIVES: In this study we aimed to investigate whether exposure to arsenic enhances the risk of ED. METHODS: We recruited 177 males >or= 50 years of age through health examinations conducted in three hospitals in Taiwan. We used a questionnaire (International Index of Erectile Function-5) to measure the level of erectile function. Sex hormones, including total testosterone and sex hormone-binding globulin, were determined by radioimmunoassay. We used another standardized questionnaire to collect background and behavioral information (e.g., cigarette smoking; alcohol, tea, or coffee drinking; and physical activity). RESULTS: The prevalence of ED was greater in the arsenic-endemic area (83.3%) than in the non-arsenic-endemic area (66.7%). Subjects with arsenic exposure > 50 ppb had a significantly higher risk of developing ED than those with exposure

The Relationship between Sex Hormones and Bone Turnover Markers in Adult Men

BACKGROUND: Bone mass changes in men is related to age, BMI, sex hormones and other factors. In prior studies, bone markers were negatively correlated with bone mineral density, free testosterone, and estrogen and was positively correlated with SHBG. In a study of sex hormones and bone markers in Korean men estradiol was negatively correlated with deoxypyridinoline. In this study, the relationship of testosterone, estradiol, calculated free testosterone, FEI and SHBG to bone turnover markers in adult men were investigated. METHODS: This was a cross-sectional study of 184 men who had undertaken a health screening program in one general hospital in Bundang from November, 2001 to February, 2003. We surveyed information concerning the past medical history, current medication, alcohol consumption amount per week and smoking amount by means of self questionnaire records. Serum total testosterone, estradiol, SHBG and osteocalcin, alkaline phosphatase were measured at a fasting state. Urine was tested for deoxypyridinoline. Free testosterone was calculated using albumin, SHBG, and total testosterone level. RESULTS: Deoxypyridinoline adjusted by age, BMI was negatively correlated with FEI (r=-0.17, P=0.020) and was positively correlated with smoking amount (r=0.20 P= 0.007). Osteocalcin was negatively correlated with calculated free testosterone and ethanol consumption amount (r=-0.186, P=.0.12, r=-0.186, P=0.012). Multiple regression analysis showed that the most powerful factor influencing deoxypyridinoline was smoking amount (R2= 0.046), followed by FEI, BMI, and the one influencing osteocalcin was BMI (R2=0.050), ethanol amount and calculated free testosterone. After adjusting for age, BMI, drinking amount and smoking amount FEI shown to be a predictor of deoxypyridinoline (beta=-0.08, p<0.01, R2=0.101). After adjusting for age, BMI, and drinking amount calculated free testosterone was shown to be a predictor of osteocalcin (beta=-0.570, P<0.01, R2=0.130) in multiple regression model. CONCLUSIONS: In adult men, FEI shown to be a predictor of deoxypyridinoline and calculated free testosterone to be a predictor of osteocalcin as an independent variable.

The Relationship among Testosterone, IGF- 1 and Fat Mass

BACGROUND: The age-related increase in fat mass seems related to decrease in hormone level. Few studies have been done in Korea concerning the association between testosterone, GH (growth hormone) and fat mass. This study was undertaken to evaluate the relationship among testosterone, IGF-1 and fat mass. METHODS: The study was performed from February to October 2001 in the Health Screening Center of Pundang CHA Hospital with 243 men as subjects. Fat intake was measured through interview with diet therapist and other data were obtained by self-questionnaire. Fat mass was measured using Inbody 3.0 and the level of total testosterone, SHBG and IGF-1 in serum were measured. RESULTS: Smoking was negatively correlated with fat mass and WHR (waist to hip ratio) (P <0.05) and fat intake was positively correlated with fat mass (P <0.05). Fat mass was negatively correlated with total testosterone, calculated free testosterone, and SHBG (gamma = 0.26; P <0.01, gamma = 0.15; P <0.05, gamma = 0.31; P <0.01). WHR was positively correlated with age (gamma =0.26; P <0.01) and negatively correlated with total testosterone, calculated free testosterone, and IGF-1 (gamma = 0.24; P <0.01, gamma = 0.20; P <0.01, gamma = 0.16; P <0.05). After adjustment for age, body mass index, smoking, and fat intake, the calculated free testosterone and IGF-1 were independently negatively correlated with fat mass (beta = 0.072; P <0.01, beta = 0.0035; P <0.05) and WHR (beta = 6.9E-04; P <0.05, beta = 4.0E-05; P <0.05) but, total testosterone and SHBG were not independently correlated with fat mass and WHR. CONCLUSION: The results indicate that the calculated free testosterone and IGF-1 can be independent determinants of fat mass and WHR in middle-aged men.