Associations of sex hormone-binding globulin and testosterone with diabetes among men and women (the Saku Diabetes study): a case control study

Association Between Low Sex Hormone-Binding Globulin and Increased Risk of Type 2 Diabetes Is Mediated by Increased Visceral and Liver Fat: Results From Observational and Mendelian Randomization Analyses

The aim of this study was to investigate the associations among sex hormone-binding globulin (SHBG), visceral adipose tissue (VAT), liver fat content, and risk of type 2 diabetes (T2D). In the Netherlands Epidemiology of Obesity study, 5,690 women (53%) and men (47%) without preexisting diabetes were included and followed for incident T2D. SHBG concentrations were measured in all participants, VAT was measured using MRI, and liver fat content was measured using proton magnetic resonance spectroscopy in a random subset of 1,822 participants. We examined associations between SHBG and liver fat using linear regression and bidirectional Mendelian randomization analyses and between SHBG and T2D using Cox regression adjusted for confounding and additionally for VAT and liver fat to examine mediation. Mean age was 56 (SD 6) years, mean BMI was 30 (SD 4) kg/m2, median SHBG was 47 (interquartile range [IQR] 34-65) nmol/L in women and 34 (26-43) nmol/L in men, and median liver fat was 3.4% (IQR 1.6-8.2%) in women and 6.0% (2.9-13.5%) in men. Compared with the highest SHBG quartile, liver fat was 2.9-fold (95% CI 2.4, 3.4) increased in women and 1.6-fold (95% CI 1.3, 1.8) increased in men, and the hazard ratio of T2D was 4.9 (95% CI 2.4, 9.9) in women and 1.8 (1.1, 2.9) in men. Genetically predicted SHBG was associated with liver fat content (women: SD -0.45 [95% CI -0.55, -0.35]; men: natural logarithm, -0.25 [95% CI -0.34, -0.16]). VAT and liver fat together mediated 43% (women) and 60% (men) of the SHBG-T2D association. To conclude, in a middle-aged population with overweight, the association between low SHBG and increased risk of T2D was, for a large part, mediated by increased VAT and liver fat.

ARTICLE HIGHLIGHTS

Assessing the causal relationship between frailty and sex hormone-binding globulin or insulin-like growth factor-1 levels: A sex-stratified bidirectional Mendelian Randomization study

BACKGROUND

The association between frailty and sex hormone-binding globulin (SHBG) or insulin-like growth factor-1(IGF-1) levels demonstrates sex differences with inconsistent conclusions. This study aims to explore the causal relationship between frailty and SHBG or IGF-1 levels through bidirectional Mendelian randomization (MR).

METHODS

We conducted two-sample bidirectional sex-stratified MR analyses using summary-level data from genome-wide association studies (GWASs) to examine the causal relationship between frailty and IGF-1 or SHBG levels, as measured by frailty index (FI) and frailty phenotype (FP). We use the random-effects inverse-variance weighted (IVW), weighted median, MR-Egger, MR-Egger intercept, and leave-one-out approaches.

RESULT

The relationship between frailty and SHBG or IGF-1 levels is inversely related, with a significant decrease in SHBG levels in females. Specifically, SHBG levels significantly decrease with FI (β = -5.49; 95 % CI: -9.67 to -1.32; FDR = 0.02) and more pronounced with FP (β = -10.14; 95 % CI: -16.16 to -4.13; FDR = 0.01), as determined by the IVW approach. However, reverse analysis shows no significant effect of IGF-1 or SHBG levels on either FI or FP (p > 0.05).

CONCLUSION

Our study indicates a negative correlation between frailty and the levels of SHBG and IGF-1. It is suggested that further research is required to establish cut-off values for SHBG and IGF-1 levels in the frailty population. This is particularly important for females at higher risk, such as those undergoing menopause, to enable comprehensive assessment and early prevention efforts. While the findings imply that reduced IGF-1 and SHBG levels may not directly contribute to frailty, it is important not to overlook the underlying mechanisms through which they may indirectly influence frailty.

Testosterone levels and risk of newly diagnosed type 2 diabetes mellitus in adult men: systematic review and meta-analysis

INTRODUCTION

Testosterone is a metabolically active hormone in males for metabolic homeostasis. Although the coexistence of low testosterone levels and type 2 diabetes mellitus (T2DM) have been associated, there are no reports that evaluate alterations in total testosterone (TT) levels and the risk of newly diagnosed T2DM. This review evaluates this question in adult men with high or low levels of total testosterone (TT), as well as the role played by other hormones such as free testosterone (FT), sex hormone binding globulin (SHBG), dihydrotestosterone (DHT), estrogens and testosterone bioavailable (bT).

METHODS

We searched for studies published up to July 30, 2023, in five databases, following a PECO strategy. We found twenty-two studies for quantitative analysis and meta-analyzed the same quantity of studies.

RESULTS

This first meta-analysis incorporates the assessment of the risk of low TT and T2DM in longitudinal studies. 43,038 adult men are included. Our meta-analysis shows that there is an association between low TT levels and the risk of newly diagnosed T2DM (OR 1.52; 95% CI 1.10-2.10; p < 0.05; I²: 79%). It is also evident that SHBG in low TT studies behaves as a risk factor for T2DM in the same way as FT, although without statistical significance. bT behaves as a protective factor. There is no association between estrogen, DHT and T2DM.

CONCLUSIONS

In adult men with low TT values, there is a greater risk of developing a newly diagnosed of T2DM. SHBG values in low TT patients also present a higher risk of T2DM as the same FT but without statistical significance. bT behaves as a protective factor We have not found an association between risk of T2DM and the levels of estrogen, DHT although there are very few studies that report these hormones.

Long-term trends in incidence, mortality and burden of liver cancer due to specific etiologies in Hubei Province

Liver cancer, a chronic non-communicable disease, represents a serious public health problem. Long-term trends in the burden of liver cancer disease are heterogeneous across regions. Incidence and mortality of liver cancer, based on the Global Burden of Disease, were collected from the Chinese Centre for Disease Control and Prevention. Age-period-cohort model was utilized to reveal the secular trends and estimate the age, period and cohort effects on primary liver cancer due to specific etiologies. Both the age-standardized incidence and mortality rate of liver cancer in Hubei province were on the rise, although there were discrepancies between gender groups. From age-period-cohort analysis, both incidence and mortality of liver cancer due to Hepatitis B virus were the highest in all age groups. The incidence of all liver cancer groups increased with time period in males, while this upward trend was observed in females only in liver cancer due to alcohol use group. Cohort effects indicated the disease burden of liver cancer decreased with birth cohorts. Local drifts showed that the incidence of liver cancer due to specific etiologies was increasing in the age group of males between 40 and 75 years old. The impact of an aging population will continue in Hubei Province. the disease burden of liver cancer will continue to increase, and personalized prevention policies must be adopted to address these changes.

Interaction between gut microbiota and sex hormones and their relation to sexual dimorphism in metabolic diseases

Metabolic diseases, such as obesity, metabolic syndrome (MetS) and type 2 diabetes (T2D), are now a widespread pandemic in the developed world. These pathologies show sex differences in their development and prevalence, and sex steroids, mainly estrogen and testosterone, are thought to play a prominent role in this sexual dimorphism. The influence of sex hormones on these pathologies is not only reflected in differences between men and women, but also between women themselves, depending on the hormonal changes associated with the menopause. The observed sex differences in gut microbiota composition have led to multiple studies highlighting the interaction between steroid hormones and the gut microbiota and its influence on metabolic diseases, ultimately pointing to a new therapy for these diseases based on the manipulation of the gut microbiota. This review aims to shed light on the role of sexual hormones in sex differences in the development and prevalence of metabolic diseases, focusing on obesity, MetS and T2D. We focus also the interaction between sex hormones and the gut microbiota, and in particular the role of microbiota in aspects such as gut barrier integrity, inflammatory status, and the gut-brain axis, given the relevance of these factors in the development of metabolic diseases.

Effect Modification by Age and Gender in the Correlation Between Diabetes Mellitus, Hypertension, and Obesity

BACKGROUND

Literature has reported differences in the epidemiology or natural history of non-communicable diseases among both the male and female sexes. Stratification of multimorbidity burden based on sex is crucial to identify and implement targeted prevention and control interventions for chronic diseases.

OBJECTIVES

To determine the burden of hypertension, type-2 diabetes mellitus, and obesity; and to compare the related multimorbidity among male and female patients.

METHODS

The study was a retrospective analysis of 375 802 medical records from primary care centers. Data was extracted from March 2022 to March 2023. A multivariate probit estimation methodology was employed using a 3-equations multivariate multiple probit model to jointly estimate the association of a person's sex with the diagnosis of the 3 chronic conditions: obesity, diabetes, and hypertension. A multinomial logistic regression analysis was conducted to allow each unique combination of these 3 chronic diseases.

RESULTS

Females had a relatively higher proportion of obesity (58.1% vs 41.2%), obesity and diabetes only (58.9% vs 41.1%), obesity and hypertension (63.6% vs 36.4%), and joint diagnosis with 3 conditions (65.7% vs 34.3%). Females' participants consistently had a significantly higher likelihood of diagnosis compared with males except for diabetes (OR = 0.59, 95% CI: 0.56-0.62) and the combination of only diabetes and hypertension (OR = 0.67, 95% CI: 0.61-0.74). The likelihood of other combinations ranged from 1.04 (95% CI: 0.98-1.10) for only hypertension to 2.30 (95% CI: 2.10-2.53) for the joint diagnosis of all 3 conditions. An increased likelihood of a single or combined occurrence of 3 chronic conditions was observed with increased age.

CONCLUSION

The multimorbidity distribution for diabetes mellitus, hypertension, and obesity differs significantly among male and female patients. The overall burden of morbidity, and mortality, however, tends to rise after 46 years of age, with the highest burden among individuals above 60 years of age.

Hyperandrogenemia in Early Adulthood Is an Independent Risk Factor for Abnormal Glucose Metabolism in Middle Age

CONTEXT

The role of androgen excess as a contributing factor to abnormal glucose metabolism (AGM) and insulin resistance in women remains controversial.

OBJECTIVE

To investigate whether hyperandrogenemia (HA) estimated by serum testosterone (T) level and free androgen index (FAI) at ages 31 and 46 years is associated with insulin resistance, insulin secretion and AGM by age 46.

DESIGN

Prospective study including 5889 females followed at ages 31 and 46 years.

SETTING

General community.

PARTICIPANTS

Women with HA were compared with normoandrogenic women at ages 31 and 46 years.

INTERVENTION

None.

MAIN OUTCOME MEASUREMENTS

AGM, including prediabetes and type 2 diabetes mellitus, homeostatic model assessments of insulin resistance (HOMA-IR) and of pancreatic β-cell function (HOMA-B).

RESULTS

At age 31 years, HA women displayed increased HOMA-IR (P = 0.002), HOMA-B (P = 0.007), and higher fasting insulin (P = 0.03) than normoandrogenic women after adjusting for body mass index (BMI). At age 46 years, there was a nonsignificant trend toward higher fasting glucose (P = 0.07) and glycated hemoglobin A1 (P = 0.07) levels in HA women. Women in the highest T quartile (odds ratio [OR] = 1.80; 95%CI, 1.15-2.82) at age 31 years and in the 2 highest FAI quartiles at ages 31 (Q4: OR = 3.76; 95% CI, 2.24-6.32) and 46 (Q4: OR = 2.79; 95% CI, 1.74-4.46) years had increased risk for AGM, independently of BMI, when compared with women in Q1. SHBG was inversely associated with AGM (at age 31 years: Q4: OR = 0.37; 95% CI, 0.23-0.60, at age 46 years: Q4: OR = 0.28; 95% CI, 0.17-0.44).

CONCLUSION

Hyperandrogenemia and low SHBG in early and middle age associates with AGM independently of BMI.

Predictive value of circulating sex hormone-binding globulin for gestational diabetes: a meta-analysis

Aim: To detect predictive value of preconception or early pregnancy sex hormone-binding globulin (SHBG) for subsequent gestational diabetes mellitus (GDM). Materials & methods: We searched Embase, Medline, PubMed, Web of Science and Cochrane library up to January 2020. Studies assessing diagnostic performance of SHBG for GDM diagnosed by well-defined diagnostic criteria using oral glucose tolerance test. Results: Totally seven studies with 1947 women were included and 247 were diagnosed as GDM. SHBG had a combined diagnostic odds ratio of 6.68 (95% CI: 4.58-9.74), sensitivity of 0.70 (95% CI: 0.51-0.84), specificity of 0.74 (95% CI: 0.52-0.88), positive likelihood ratio of 2.49 (95% CI: 1.73-3.57) and negative likelihood ratio of 0.37 (95% CI: 0.23-0.61). The area under the summary receiver operating characteristic curve was 0.78 (95% CI: 0.74-0.82). Conclusion: SHBG had a predictive value for GDM and might improve GDM screening. However, heterogeneity between studies warrants more research into this topic.

Serum progesterone and retinopathy in male patients with type 2 diabetes: A cross-sectional study

AIMS/INTRODUCTION

The aim of this study was to investigate the relationship between serum progesterone (P) and retinopathy in male patients with type 2 diabetes mellitus, and to investigate whether P is associated with its progression.

MATERIALS AND METHODS

A total of 1,376 male participants with type 2 diabetes mellitus were recruited from Affiliated Hospital of Medical College Qingdao University (Qingdao, China). Through logistic regression analysis after adjusting the potential confounding variation, the odds ratio (OR) and the corresponding 95% confidence interval related to the quartiles of progesterone were obtained.

RESULTS

According to the quartiles of P levels, the prevalence rate of diabetic retinopathy (DR) in the last quartile is obviously greater to other quartiles (52.5-34.9%, 31.9%, 37.5%, P < 0.001). Compared with those in the first quartile, the prevalence of DR for the last quartile had an OR of 1.85 in the non-proliferative diabetic retinopathy group, while the OR was 8.35 in the proliferative diabetic retinopathy group (P < 0.001, unadjusted model). When adjusted for age, body mass index, duration of type 2 diabetes mellitus, glycated hemoglobin, blood pressure and other variables, the ORs for DR in the fourth quartile were 2.13 (95% confidence interval 1.49-3.06) in the non-proliferative diabetic retinopathy group and 8.44 (95% confidence interval 2.69-26.43) in the proliferative diabetic retinopathy group (P < 0.001). The positive association between P and DR risk was independent in adjusted logistic regression.

CONCLUSIONS

High levels of serum progesterone are significantly associated with DR in male hospitalized patients. This could mean that a higher P level in men is a potential clinical factor to identify DR, and the causality remains to be further explored.

Dietary glycemic index, glycemic load, insulin index, insulin load and risk of diabetes-related cancers: A systematic review of cohort studies

BACKGROUND & AIMS

It is believed that diets high in glycemic index (GI), glycemic load (GL), Insulin index (II), and Insulin load (IL) are associated with the increased risks of certain cancers through increasing serum glucose or insulin levels.

METHODS

We conducted this systematic review of cohort studies to evaluate the possible relation between GI, GL, II, and IL with diabetes-related cancers, including colorectal, bladder, breast, endometrium, liver, pancreas, and prostate cancers. Two separate investigators conducted a literature search through PubMed/Medline, Scopus, and Web of Science databases up to February 2020, plus reference lists of relevant articles.

RESULTS

Fifty-three cohort studies with a total of 100 098 cancer cases were included in this systematic review. Fifteen out of eighteen studies among breast cancer cases reported no significant association between GI/GL and cancer risk. These numbers were 4 out of 13 for colorectal cancer, 7 out of 9 for endometrial cancer, 2 out of 3 for liver cancer, 8 out of 10 for pancreatic cancer, and 3 out of 3 for prostate cancer. Only one cohort investigated this association in terms of bladder cancer and reported a significant association. Also, five studies reported this relation in terms of II/IL, and only one cohort among endometrial cancer patients observed a significant positive association between the risk of cancer and IL.

CONCLUSION

We concluded a weak association between dietary GI/GL and no association between II/IL with diabetes-related cancer risk. More cohort studies are required to be performed regarding II/IL and the risk of cancer.

Association between testosterone with type 2 diabetes in adult males, a meta-analysis and trial sequential analysis

OBJECTIVE

We performed this meta-analysis to assess serum testosterone changes in adult males with Type 2 diabetes (T2DM).

METHODS

PubMed, Embase, Web of Science, and Cochrane Library were searched to identify qualified studies. Pooled weighted mean differences (WMDs) with 95% confidence intervals (CIs) were utilized to test the changes of total testosterone (TT), free testosterone (FT) and sex hormone-binding globulin (SHBG) in patients with T2DM. Besides, trial sequential analysis was used to verify the pooled results.

RESULTS

A total of 56 studies were enrolled in our meta-analysis. Meta-analyses of the cross-sectional studies showed that patients with T2DM has significant decreases in TT (WMD: -2.98, 95%CI: -3.48 to -2.47), FT (WMD: -32.82, 95%CI: -39.70 to -25.95) and SHBG (WMD: -2.47, 95%CI: -3.93 to -1.02). In terms of the prospective studies, our results showed decreases in TT (WMD: -2.35, 95%CI: -3.24 to -1.46), FT (WMD: -25.96, 95%CI: -83.98 to 32.05), and SHBG (WMD: -10.06, 95%CI: -13.29 to -6.84) in patients with T2DM. By trial sequential analyses, the findings in current meta-analysis were based on reliable evidence.

CONCLUSION

Our results indicate that patients with T2DM have lower serum TT, FT, and SHBG levels.

Association of total testosterone, free testosterone, bioavailable testosterone, sex hormone-binding globulin, and hypertension

Low testosterone has been inversely associated with hypertension. Our objective was to determine the associations between total testosterone (TT), free testosterone (FT), bioavailable testosterone (BioT), sex hormone-binding globulin (SHBG), and hypertension. Two hundred fifty-three men were enrolled in this study. TT and SHBG were measured by chemiluminescent immunoassay, and FT and BioT were calculated. Hypertension was defined as systolic blood pressure (SBP) ≥140 mm Hg and/or diastolic blood pressure (DBP) ≥90 mm Hg. Our results showed that hypertensive men had higher SHBG levels, and lower FT and BioT, compared to normotensive men. FT and BioT were inversely associated with SBP and DBP after adjusting for covariates (age, smoking, alcohol consumption, and physical activity). Furthermore, there was a significant decrease in the odds ratios for hypertension in the third and fourth quartiles of BioT and FT, compared to the lowest quartile before and after adjusting for covariates. In contrast, the OR for hypertension in the third quartile of SHBG was lower than the highest quartile. Our data show that FT and BioT are inversely correlated with SBP, DBP, and hypertension in men.

Association of total testosterone, free testosterone, bioavailable testosterone and sex hormone-binding globulin with hepatic steatosis and the ratio of aspartate aminotransferase to alanine aminotransferase

Several articles have shown the inverse association between total testosterone (TT) or sex hormone-binding globulin (SHBG) and hepatic steatosis. No articles report associations of TT, SHBG, free testosterone (FT), and bioavailable testosterone (BioT) with aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratios. Therefore, we investigated the associations of TT, FT, BioT and SHBG with hepatic steatosis and AST/ALT ratios. A total of 218 men were enrolled. We diagnosed hepatic steatosis by ultrasound. TT and SHBG showed a reduced risk for hepatic steatosis when analyzed with or without adjusting for age, smoking, alcohol consumption and physical activity. Compared with the lowest quartile, the ORs for hepatic steatosis in the third and fourth quartiles (0.32 [95% CI: 0.14-0.75] and 0.27 [95% CI: 0.10-0.73], respectively) of SHBG were significantly lower after adjustments. The OR for hepatic steatosis in the fourth quartile of TT (0.41 [95% CI: 0.17-0.95]) was significantly lower than in the lowest quartile after adjustments. The mean AST/ALT ratios in men with hepatic steatosis were lower than those without hepatic steatosis (0.83 and 1.04, respectively), due to the elevated ALT levels in hepatic steatosis groups. Furthermore, TT and SHBG were positively associated with AST/ALT ratios with and without adjustments. In conclusion, higher TT and SHBG levels in men are associated with the reduced risk of hepatic steatosis and elevated AST/ALT ratios, independent of age, smoking, alcohol consumption and physical activity.

Risk factors for late-onset hypogonadism

The European Male Aging Study (EMAS) has recently defined strict diagnostic criteria for late-onset hypogonadism (LOH) including the levels of serum total testosterone (TT), free testosterone (FT) and three sexual symptoms. However, there is no report on risk factors for LOH using these criteria. In this study, we investigated risk factors for LOH based on these criteria. We recruited 277 men (aged 36-80 years) who completed both a health check-up and two questionnaires (a health and lifestyle questionnaire, and a sexual function questionnaire). Data on parameters, such as systolic blood pressure (SBP), glucose, triglyceride (TG) and high-density lipoprotein (HDL), were obtained from medical records of the hospital in Shantou. TT and sex hormone-binding globulin (SHBG) were measured by chemiluminescent immunoassay, and FT was calculated. TT, FT, age, waist circumference, SBP and glucose showed significant differences between LOH-positive and LOH-negative individuals. Univariate regression analyses showed that age, waist circumference, SBP, glucose and health status were risk factors for LOH. Pearson's correlation analysis revealed that TT was inversely correlated with waist circumference, glucose and SBP, and FT was inversely correlated with age, SBP and health status. In conclusion, age, waist circumference, SBP, glucose and health status were risk factors for LOH.

The role of sex hormone-binding globulin (SHBG), testosterone, and other sex steroids, on the development of type 2 diabetes in a cohort of community-dwelling middle-aged to elderly men

AIMS

Contrasting findings exist regarding the association between circulating sex hormone-binding globulin (SHBG) and testosterone levels and type 2 diabetes (T2D) in men. We examined prospective associations of SHBG and sex steroids with incident T2D in a cohort of community-dwelling men.

METHODS

Participants were from a cohort study of community-dwelling (n = 2563), middle-aged to elderly men (35-80 years) from Adelaide, Australia (the Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) study). The current study included men who were followed for 5 years and with complete SHBG and sex steroid levels (total testosterone (TT), dihydrotestosterone (DHT) and oestradiol (E2)), but without T2D at baseline (n = 1597). T2D was identified by either self-report, fasting glucose (≥ 7.0 mmol/L), HbA1c (≥ 6.5%/48.0 mmol/mol), and/or prescriptions for diabetes medications. Logistic binomial regression was used to assess associations between SHBG, sex steroids and incident T2D, adjusting for confounders including age, smoking status, physical activity, adiposity, glucose, triglycerides, symptomatic depression, SHBG and sex steroid levels.

RESULTS

During an average follow-up of 4.95 years, 14.5% (n = 232) of men developed new T2D. Multi-adjusted models revealed an inverse association between baseline SHBG, TT, and DHT levels, and incident T2D (odds ratio (OR) = 0.77, 95% CI [0.62, 0.95], p = 0.02; OR 0.70 [0.57, 0.85], p < 0.001 and OR 0.78 [0.63, 0.96], p = 0.02), respectively. However, SHBG was no longer associated with incident T2D after additional adjustment for TT (OR 0.92 [0.71, 1.17], p = 0.48; TT in incident T2D: OR 0.73 [0.57, 0.92], p = 0.01) and after separate adjustment for DHT (OR 0.83 [0.64, 1.08], p = 0.16; DHT in incident T2D: OR 0.83 [0.65, 1.05], p = 0.13). There was no observed effect of E2 in all models of incident T2D.

CONCLUSIONS

In men, low TT, but not SHBG and other sex steroids, best predicts the development of T2D after adjustment for confounders.

Cross-sectional and longitudinal determinants of serum sex hormone binding globulin (SHBG) in a cohort of community-dwelling men

Despite its widespread clinical use, there is little data available from population-based studies on the determinants of serum sex hormone binding globulin (SHBG). We aimed to examine multifactorial determinants of circulating SHBG levels in community-dwelling men. Study participants comprised randomly selected 35–80 y.o. men (n = 2563) prospectively-followed for 5 years (n = 2038) in the Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) study. After excluding men with illness or medications known to affect SHBG (n = 172), data from 1786 men were available at baseline, and 1476 at follow-up. The relationship between baseline body composition (DXA), serum glucose, insulin, triglycerides, thyroxine (fT4), sex steroids (total testosterone (TT), oestradiol (E2)), and pro-inflammatory cytokines and serum SHBG level at both baseline & follow-up was determined by linear and penalized logistic regression models adjusting for age, lifestyle & demographic, body composition, metabolic, and hormonal factors. Restricted cubic spline analyses was also conducted to capture possible non-linear relationships. At baseline there were positive cross-sectional associations between age (β = 0.409, p<0.001), TT (β = 0.560, p<0.001), fT4 (β = 0.067, p = 0.019) and SHBG, and negative associations between triglycerides (β = -0.112, p<0.001), abdominal fat mass (β = -0.068, p = 0.032) and E2 (β = -0.058, p = 0.050) and SHBG. In longitudinal analysis the positive determinants of SHBG at 4.9 years were age (β = 0.406, p = <0.001), TT (β = 0.461, p = <0.001), and fT4 (β = 0.040, p = 0.034) and negative determinants were triglycerides (β = -0.065, p = 0.027) and abdominal fat mass (β = -0.078, p = 0.032). Taken together these data suggest low SHBG is a marker of abdominal obesity and increased serum triglycerides, conditions which are known to have been associated with low testosterone and low T4.

Genetic variants in sex hormone pathways and the risk of type 2 diabetes among African American, Hispanic American, and European American postmenopausal women in the US

BACKGROUND

Sex hormones are implicated in the development of diabetes. However, whether genetic variations in sex hormone pathways (SHPs) contribute to the risk of type 2 diabetes mellitus (T2DM) remains to be determined. This study investigated associations between genetic variations in all candidate genes in SHPs and T2DM risk among a cohort of women participating in the Women's Health Initiative (WHI).

METHODS

Single nucleotide polymorphisms (SNPs) located within 30 kb upstream and downstream of SHP genes were comprehensively examined in 8180 African American, 3498 Hispanic American, and 3147 European American women in the WHI. In addition, whether significant SNPs would be replicated in independent populations was examined.

RESULTS

After adjusting for age, region, and ancestry estimates and correcting for multiple testing, seven SNPs were significantly associated with the risk of T2DM among Hispanic American women were identified in the progesterone receptor (PGR) gene, with rs948516 showing the greatest significance (odds ratio 0.67; 95% confidence interval 0.57-0.78; P = 8.8 × 10^-7 ; false discovery rate, Q = 7.8 × 10^-4 ). These findings were not replicated in other ethnic groups in the WHI or in sex-combined analyses in replication studies.

CONCLUSION

Significant signals were identified implicating the PGR gene in T2DM development in Hispanic American women in the WHI, which are consistent with genome-wide association studies findings linking PGR to glucose homeostasis. Nevertheless, the PGR SNPs-T2DM association was not statistically significant in other ethnic populations. Further studies, especially sex-specific analyses, are needed to confirm the findings and clarify the role of SHPs in T2DM.

Testosterone level and risk of type 2 diabetes in men: a systematic review and meta-analysis

BACKGROUND

Type 2 diabetes is a risk factor for testosterone deficiency and impaired sex steroid status. Some studies also investigated the association of testosterone level with diabetes risk in men, but reported controversial findings. To clarify this issue, we conducted a systematic review and meta-analysis.

METHODS

PubMed, EMBASE and Web of Science were searched for eligible cohort or nested case-control studies published up to August 15, 2017. Meta-analysis was used to calculate the pooled relative risk (RR) of type 2 diabetes associated with higher testosterone level.

RESULTS

Thirteen cohort or nested case-control studies with 16,709 participants were included. Meta-analysis showed that higher total testosterone level could significantly decrease the risk of type 2 diabetes in men (RR = 0.65; 95% CI 0.50-0.84; P = 0.001), and higher free testosterone level could also decrease the risk of type 2 diabetes in men (RR = 0.94; 95% CI 0.90-0.99; P = 0.014). After excluding two studies that did not calculate RRs by quartiles of testosterone levels, both higher total testosterone and free testosterone levels could decrease the risk of type 2 diabetes in men, and the pooled RRs were 0.62 (95% CI 0.51-0.76; P < 0.001) and 0.77 (95% CI 0.61-0.98; P = 0.03), respectively.

CONCLUSION

This meta-analysis suggests that higher testosterone level can significantly decrease the risk of type 2 diabetes in men. Therefore, combined with previous researches, the findings above suggest a reverse-causality scenario in the relation between testosterone deficiency and risk of type 2 diabetes in men.

Cross-sectional study of the determinants and associations of sex hormone-binding globulin concentrations in first degree relatives (FDR) of patients with Type 2 Diabetes Mellitus

AIMS

This study explores the determinants of sex hormone binding globulin (SHBG) and associations with categories of glucose intolerance and undiagnosed diabetes in first-degree relatives (FDR) of patients with Type 2 Diabetes Mellitus (T2D).

METHODS

Anthropometric indices, fasting lipids, glucose, insulin, adiponectin, leptin, SHBG, estradiol (E2), testosterone (TT), androstenedione (AND), dehydroepiandrosterone sulphate (DHEA-S), high-sensitivity C-reactive protein (hs-CRP) and alanine aminotransferase (ALT) were measured in 584 FDR. Homeostasis model assessment-estimate of insulin resistance (HOMA-IR), beta cell function (%B), insulin sensitivity (%S) and free androgen index (FAI) were calculated.

RESULTS

266 subjects were normoglycemic; 237 had prediabetes and 81 had undiagnosed diabetes. SHBG decreased stepwise with worsening categories of glucose intolerance in females whereas FAI decreased stepwise with worsening categories in males only. SHBG showed significant positive correlations with adiponectin, and HDL-C and significant negative correlations with body mass index (BMI), waist circumference (WC), Waist:hip ratio (WHR), ALT, triglycerides (TG), %B, leptin and FAI. After adjustment for WHR, only HDL-C and FAI in men and FAI and HbA1c in females remained significantly associated with SHBG. Receiver Operating Characteristic (ROC) curve analysis for detection of diabetes showed that areas under the curve for FAI and SHBG were 0.711 and 0.386 for males and 0.430 and 0.660 for females respectively.

CONCLUSION

Associations of SHBG with some anthropometric and metabolic variables in FDR suggests that lower levels is a marker for risk of developing T2D through obesity dependent metabolic pathways but low FAI is a better marker of state of diabetes in males.

NAFLD as a Sexual Dimorphic Disease: Role of Gender and Reproductive Status in the Development and Progression of Nonalcoholic Fatty Liver Disease and Inherent Cardiovascular Risk

Nonalcoholic fatty liver disease (NAFLD) spans steatosis through nonalcoholic steatohepatis, cirrhosis, and hepatocellular carcinoma (HCC) associated with striking systemic features and excess cardiovascular and liver-related mortality. The pathogenesis of NAFLD is complex and multifactorial. Endocrine derangements are closely linked with dysmetabolic traits. For example, in animal and human studies, female sex is protected from dysmetabolism thanks to young individuals’ ability to partition fatty acids towards ketone body production rather than very low density lipoprotein (VLDL)-triacylglycerol, and to sex-specific browning of white adipose tissue. Ovarian senescence facilitates both the development of massive hepatic steatosis and the fibrotic progression of liver disease in an experimental overfed zebrafish model. Consistently, estrogen deficiency, by potentiating hepatic inflammatory changes, hastens the progression of disease in a dietary model of nonalcoholic steatohepatitis (NASH) developing in ovariectomized mice fed a high-fat diet. In humans, NAFLD more often affects men; and premenopausal women are equally protected from developing NAFLD as they are from cardiovascular disease. It would be expected that early menarche, definitely associated with estrogen activation, would produce protection against the risk of NAFLD. Nevertheless, it has been suggested that early menarche may confer an increased risk of NAFLD in adulthood, excess adiposity being the primary culprit of this association. Fertile age may be associated with more severe hepatocyte injury and inflammation, but also with a decreased risk of liver fibrosis compared to men and postmenopausal status. Later in life, ovarian senescence is strongly associated with severe steatosis and fibrosing NASH, which may occur in postmenopausal women. Estrogen deficiency is deemed to be responsible for these findings via the development of postmenopausal metabolic syndrome. Estrogen supplementation may at least theoretically protect from NAFLD development and progression, as suggested by some studies exploring the effect of hormonal replacement therapy on postmenopausal women, but the variable impact of different sex hormones in NAFLD (i.e., the pro-inflammatory effect of progesterone) should be carefully considered.

Socioeconomic Deprivation as Measured by the Index of Multiple Deprivation and Its Association with Low Sex Hormone Binding Globulin in Women

Objective:

Sex hormone binding globulin (SHBG) is a marker of insulin resistance. Given established links between BMI and socioeconomic disadvantage, we investigated how SHBG varies by index of multiple deprivation (IMD).

Research Design and Methods:

Using laboratory data from a Midlands UK population of mixed ethnicity, we examined the relation between blood concentrations of SHBG and IMD in 1160 women aged between 17 and 71 years. Women with a serum SHBG >250 nmol/L were excluded.

Results:

Mean age was 28.7 (95% confidence interval (CI) 28.2–29.1) years. 48.2% of women were of Caucasian origin, 15.5% of Southern Asian ethnicity and 2.6% were of African or other origin (33.7% were of unknown origin).

SHBG increased with age (Spearman’s ρ=0.195; p<0.001). A higher proportion of women of South Asian origin versus other ethnic groups had an SHBG <30 nmol/L (OR 1.93 (95% CI 1.37–2.71)).

SHBG level was lower in individuals with greater socioeconomic disadvantage as measured by IMD (Spearman's ρ= -0.09; p=0.004 for SHBG versus IMD).

In multivariate logistic regression, IMD women in the quartiles 2–5 (higher socioeconomic disadvantage) were more likely to have an SHBG <30 nmol/L (compatible with significant insulin resistance) versus quartile 1 (odds ratio (OR) 1.71 (95% confidence interval (CI) 1.17–2.53), adjusted for age (OR=0.97 (95% CI 0.95–0.98)) and ethnicity (for South Asian ethnicity OR=2.00 (95% CI 1.42–2.81) versus the rest).

Conclusion:

Lower SHBG levels in women are associated with a higher level of socioeconomic disadvantage. Given the known association between lower SHBG and higher plasma glucose, our findings suggest a link between socioeconomic disadvantage and future risk of type 2 diabetes.

Steroid Sex Hormones, Sex Hormone-Binding Globulin, and Diabetes Incidence in the Diabetes Prevention Program

CONTEXT

Steroid sex hormones and SHBG may modify metabolism and diabetes risk, with implications for sex-specific diabetes risk and effects of prevention interventions.

OBJECTIVE

This study aimed to evaluate the relationships of steroid sex hormones, SHBG and SHBG single-nucleotide polymorphisms (SNPs) with diabetes risk factors and with progression to diabetes in the Diabetes Prevention Program (DPP).

DESIGN AND SETTING

This was a secondary analysis of a multicenter randomized clinical trial involving 27 U.S. academic institutions.

PARTICIPANTS

The study included 2898 DPP participants: 969 men, 948 premenopausal women not taking exogenous sex hormones, 550 postmenopausal women not taking exogenous sex hormones, and 431 postmenopausal women taking exogenous sex hormones.

INTERVENTIONS

Participants were randomized to receive intensive lifestyle intervention, metformin, or placebo.

MAIN OUTCOMES

Associations of steroid sex hormones, SHBG, and SHBG SNPs with glycemia and diabetes risk factors, and with incident diabetes over median 3.0 years (maximum, 5.0 y).

RESULTS

T and DHT were inversely associated with fasting glucose in men, and estrone sulfate was directly associated with 2-hour post-challenge glucose in men and premenopausal women. SHBG was associated with fasting glucose in premenopausal women not taking exogenous sex hormones, and in postmenopausal women taking exogenous sex hormones, but not in the other groups. Diabetes incidence was directly associated with estrone and estradiol and inversely with T in men; the association with T was lost after adjustment for waist circumference. Sex steroids were not associated with diabetes outcomes in women. SHBG and SHBG SNPs did not predict incident diabetes in the DPP population.

CONCLUSIONS

Estrogens and T predicted diabetes risk in men but not in women. SHBG and its polymorphisms did not predict risk in men or women. Diabetes risk is more potently determined by obesity and glycemia than by sex hormones.

The evaluation of serum levels of testosterone in type 2 diabetic men and its relation with lipid profile

INTRODUCTION AND AIM

Type 2 diabetes mellitus (T2DM) is the predominant form of diabetes worldwide and much is known about its patho-physiology. Yet, newer aspects related to it are being constantly explored. For ages, testosterone has been known to men as the male sex hormone but now it has been shown by certain studies that it might have a role in the development of metabolic disorders like type 2 diabetes. This study was carried out to determine the relation of testosterone levels with type 2 diabetes mellitus and lipid profile in North East Indian men aged 31 to 73 years.

MATERIALS AND METHODS

This case control study comprised of 40 type 2 diabetic men and 40 age matched non diabetic healthy men. Testosterone, SHBG levels and lipid profile were evaluated in both the groups along with anthropometric measurements and were statistically analysed.

RESULTS

Serum total and free testosterone and Sex Hormone Binding Globulin were significantly lower in the test group than in the control group. Prevalence of type 2diabetes was five times higher in men having a total testosterone less than 8nmol/L and 5.57 times higher in those having a free testosterone of less than 0.225nmol/L. Fasting blood glucose showed a strong negative correlation with total and free testosterone. Glycated haemoglobin correlated negatively with SHBG but no such correlation was seen with total or free testosterone. Serum total and LDL cholesterol showed significant negative correlation with total testosterone and SHBG but no significant correlation was found with free testosterone. Serum VLDL, HDL and triglycerides did not show any significant correlation with total or free testosterone and SHBG levels.

CONCLUSION

Low testosterone might have a role in the development of type 2 DM and to the associated altered lipid profile. This study, though a small one is among the few of its kind in India and it thrives to assist other studies related to the matter.

Sex steroids and glucose metabolism

Testosterone levels are lower in men with metabolic syndrome and type 2 diabetes mellitus (T2DM) and also predict the onset of these adverse metabolic states. Body composition (body mass index, waist circumference) is an important mediator of this relationship. Sex hormone binding globulin is also inversely associated with insulin resistance and T2DM but the data regarding estrogen are inconsistent. Clinical models of androgen deficiency including Klinefelter's syndrome and androgen deprivation therapy in the treatment of advanced prostate cancer confirm the association between androgens and glucose status. Experimental manipulation of the insulin/glucose milieu and suppression of endogenous testicular function suggests the relationship between androgens and insulin sensitivity is bidirectional. Androgen therapy in men without diabetes is not able to differentiate the effect on insulin resistance from that on fat mass, in particular visceral adiposity. Similarly, several small clinical studies have examined the efficacy of exogenous testosterone in men with T2DM, however, the role of androgens, independent of body composition, in modifying insulin resistance is uncertain.

Low serum sex hormone-binding globulin is associated with nonalcoholic fatty liver disease in type 2 diabetic patients

INTRODUCTION

Studies have indicated that low serum sex hormone-binding globulin (SHBG) and testosterone levels are associated with nonalcoholic fatty liver disease (NAFLD). However, it remains unclear whether an association exists between SHBG and NAFLD independent of testosterone.

OBJECTIVE

This study was aimed to investigate the relationship between SHBG and both total and free testosterone levels with NAFLD.

SUBJECTS AND MEASURES

One hundred and twenty patients with NAFLD and 120 age-, sex- and BMI-matched patients with non-NAFLD were enrolled into a case-control study. Serums SHBG, total testosterone (TT), liver enzymes, lipids, insulin, C-peptide and plasma glucose were measured. Free testosterone (FT) and fatty liver index were calculated.

RESULTS

Serum SHBG levels were significantly lower in NAFLD group than in non-NAFLD group (24·5 ± 11·0 vs 37·6 ± 14·4 nm, P < 0·001). After adjustment for age, smoking status, alcohol use, duration of diabetes, BMI and fasting C-peptide, serum SHBG levels in men and women were inversely associated with NAFLD, with odds ratio (OR) and 95% confidence interval (CI) in the forth quartile as 0·05 (0·01-0·30) and 0·25 (0·08-0·77) compared with the first quartile (OR = 1·00). Additional adjustment for TT in men and FT in women did not materially alter the association. The relationship between serum TT (for men) and FT (for women) with NAFLD was attenuated and even diminished after multivariable adjustment for known risk factors and SHBG.

CONCLUSION

Low serum SHBG levels, but not TT or FT, are associated with NAFLD in type 2 diabetic patients.

Testosterone and type 2 diabetes in men

OBJECTIVE

To assess from observational data if low testosterone in men is an independent risk factor for high fasting glucose (FG) and for a diagnosis of type 2 diabetes (T2D).

METHODS

Multivariate analysis of data from 991 male US Air Force veterans who completed six medical examinations over 20 years.

RESULTS

Low testosterone was moderately related to high FG, independent of age and obesity. Low testosterone is a very weak predictor of a diagnosis of T2D.

CONCLUSIONS

In men, low testosterone is an independent risk factor for high FG, comparable to aging and obesity. Low testosterone is a weak predictor of a diagnosis of T2D.

Prostate cancer risk in pre-diabetic men: a matched cohort study

BACKGROUND

Diagnosis and duration of type 2 diabetes mellitus (DM) appear to be associated with decreased prostate cancer risk. Limitations of previous studies include methods of subject selection and accurate definition of DM diagnosis. We examined the temporal relationship between DM and prostate cancer risk exploring the period of greatest risk starting from the prediabetic to the post-diabetic period using clinical and administrative data to accurately define the date of DM diagnosis.

METHODS

We identified 5,813 men who developed DM between January 1, 1995 and December 31, 2009 (reference date, date of DM onset or matched date for non-diabetic cohort) and 28,019 non-diabetic men matched by age, smoking history, residence, and reference date. Prostate cancer incidence before and after the reference date was assessed using Cox regression modeling adjusted for matching variables, body mass index, insurance status, and comorbidities. Primary outcomes included hazard ratio (HR) and number needed to be exposed to DM for one additional person to be harmed (NNEH) or benefit (NNEB) with respect to prostate cancer risk.

RESULTS

After full adjustment, the HR for prostate cancer before DM diagnosis was 0.96 (95% CI 0.85-1.08; P=0.4752), and the NNEB was 974 at DM diagnosis. After the reference date, the fully-adjusted HR for prostate cancer in diabetic men was 0.84 (95% CI 0.72-0.97, P=0.0167), and the NNEB 3 years after DM onset was 425. The NNEB continued to decrease over time, reaching 63 at 15 years after DM onset, suggesting an increasing protective effect of DM on prostate cancer risk over time. No significant difference between the diabetic and non-diabetic cohort was found prior to reference date.

CONCLUSION

Prostate cancer risk is not reduced in pre-diabetic men but decreases after DM diagnosis and the protective effect of DM onset on prostate cancer risk increases with DM duration.