Associations of estrogen and testosterone with insulin resistance in pre- and postmenopausal women with and without hormone therapy

Aerobic exercise with diet induces hormonal, metabolic, and psychological changes in postmenopausal obese women

Physical activity and diet are recommended lifestyle strategies to improve human health. Consequently, this study aimed to investigate the impact of aerobic exercise combined with dietary restriction on hormonal, metabolic, and psychological variables in postmenopausal women. Eligible 60 women were enrolled and assigned into two equal groups; the experimental group performed aerobic exercise three times per week for 12 weeks with diet restriction, and the control group only received the same diet program. Serum levels of sex hormones, insulin resistance, and depression scores were measured before and after the intervention.

Results

All measured variables were significantly changed in the experimental group compared to the control group (P = 0.001).

Conclusion

Changes in sex hormones are a biological marker of metabolic complications such as insulin resistance, which can be reduced with exercise and diet. In addition, they are effective therapeutic interventions in the treatment of mild depression.

Trial registration

Registration identifier number of this study is: NCT05136742 on https://register.ClinicalTrials.gov.

Pathophysiology of Physical Inactivity-Dependent Insulin Resistance: A Theoretical Mechanistic Review Emphasizing Clinical Evidence

The modern lifestyle has a negative impact on health. It is usually accompanied by increased stress levels and lower physical activity, which interferes with body homeostasis. Diabetes mellitus is a relatively common metabolic disorder with increasing prevalence globally, associated with various risk factors, including lower physical activity and a sedentary lifestyle. It has been shown that sedentary behavior increases the risk of insulin resistance, but the intermediate molecular mechanisms are not fully understood. In this mechanistic review, we explore the possible interactions between physical inactivity and insulin resistance to help better understand the pathophysiology of physical inactivity-dependent insulin resistance and finding novel interventions against these deleterious pathways.

Sex Hormone-Binding Globulins and Testosterone Levels as a Risk Marker for Type 2 Diabetes Mellitus among Postmenopausal Women

BACKGROUND

Endogenous sex hormones and sex hormone-binding globulins (SHBG) determine the risk of occurrence of Type 2 diabetes mellitus (T2DM) in postmenopausal (PM) women.

AIMS

To investigate the association between sex hormones (estradiol and testosterone) and SHBG with plasma glucose, fasting insulin levels, HbA1c, and homeostasis model assessment insulin resistance (HOMA-IR) and also to investigate independent role of sex hormones in the occurrence of T2DM among PM.

SETTINGS AND DESIGN

Cross-sectional case-control study.

SUBJECTS AND METHODS

The present study was conducted in Endocrinology department Guwahati, Medical College, Assam, India. The participants included cases - PM women with T2DM (n = 100) and controls - Healthy PM women (n = 86). The medical history, clinical examination, and investigations including total testosterone, serum estradiol, SHBG, free testosterone index, high sensitivity C-reactive protein (hs-CRP), lipid profile, fasting insulin, fasting plasma glucose (FPG), and postprandial plasma glucose (PPPG) were done and analyzed. HOMA-IR was calculated.

STATISTICAL ANALYSIS

Pearson correlation between sex hormone level and SHBG with plasma glucose, HbA1c, fasting insulin, hs-CRP, and HOMA-IR was seen. Multivariance logistic analysis was done to find the independent association between sex hormones/SHBG and the occurrence of T2 DM. P < 0.05 was considered statistically significant.

RESULTS

Among the cases, a significant positive correlation was found between total testosterone/free testosterone index with waist circumference, FPG PPPG, HbA1c, fasting insulin, and HOMA-IR, and a significant negative correlation was found between SHBG and FPG, PPPG, HbA1c, fasting insulin, and HOMA-IR (P < 0.01). The logistic analysis showed total testosterone levels and SHBG are independently associated with the occurrence of T2 DM among PM (P < 0.01).

CONCLUSION

SHBG and testosterone levels in PM can be a risk marker for the development of T2DM.

Elevated circulating luteinizing hormone levels are associated with diabetic macroalbuminuria in Chinese men and postmenopausal women: A cross-sectional study

BACKGROUND

Associations between sex hormones and diabetic vascular complications have recently been studied, but the role luteinizing hormone (LH) plays in diabetic kidney disease (DKD) remains uncertain. We aimed to investigate the relationship of LH and DKD in Chinese men and postmenopausal women with type 2 diabetes mellitus (T2DM).

METHODS

Data were collected from 1775 T2DM men and postmenopausal women in hospital. The odds ratios (OR) and corresponding 95% confidence intervals (CI) in relation to LH quartiles were obtained by multiple logistic regression analysis.

RESULTS

LH levels were significantly higher in patients with macroalbuminuria than in those with microalbuminuria, but were not higher in patients with microalbuminuria than in those with normoalbuminuria. Consistently, LH in those with an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m² were significantly higher than in those with eGFR≥60 mL/min/1.73m² . The prevalence of macroalbuminuria was obviously increased for subjects of the fourth quartile of LH vs the first to third quartile (20.4% vs 6.2%, 8.0%, 12.2% in men; 25.3% vs 5.5%, 3.8%, 9.3% in postmenopausal women). Multivariate logistic regression demonstrated that subjects within the highest quartile of LH had higher odds of macroalbuminuria than those within the lowest quartile (OR 4.00, 95% CI, 1.87-8.55 for men; OR 9.62, 95% CI, 3.42-27.08 for postmenopausal women), independent of age, diabetes duration, or other metabolic factors. The area under the curve for detecting macroalbuminuria based on LH was 0.662 for men, and 0.767 for postmenopausal women.

CONCLUSION

High LH levels are positively associated with established DKD among Chinese men and postmenopausal women. Elevated LH may be a promising clinical factor for identifying established DKD.

Sex hormone levels and risk of primary open-angle glaucoma in postmenopausal women

OBJECTIVE

We evaluated the relation of prediagnostic sex hormone levels in postmenopausal women with primary open-angle glaucoma (POAG) and intraocular pressure (IOP).

METHODS

Among postmenopausal participants of the Nurses' Health Study, POAG cases (n = 189; diagnosed 1990-2008) and controls (n = 189) were matched on age, fasting status, and postmenopausal hormone use at blood draw (1989-1990). Plasma concentrations of estrone sulfate, estradiol, testosterone, sex hormone binding globulin, and dehydroepiandrosterone sulfate were assessed. The primary outcome was POAG; in secondary analyses, among cases only, we evaluated maximum untreated IOP at diagnosis. Multivariable-adjusted logistic/multiple linear regression models were used to evaluate tertiles (Ts) of biomarker levels and the two outcomes, adjusting for various potential confounders.

RESULTS

We observed no significant associations of estrone, estradiol, sex hormone binding globulin, or dehydroepiandrosterone sulfate with POAG risk or with maximum IOP at glaucoma diagnosis among cases. Suggestive significant associations were observed with highest testosterone and POAG risk (T3 vs T1 multivariable-adjusted odds ratio 1.84; 95% confidence interval 1.02, 3.33; P trend 0.10). Similarly, for maximum IOP at diagnosis among cases only (mean 8 years after blood draw), higher testosterone was significantly associated with higher IOP (multivariable-adjusted difference in IOP T3 vs T1 2.17 mm Hg; 95% confidence interval 0.34, 3.99; P trend 0.02).

CONCLUSIONS

Overall, plasma sex hormone levels in postmenopausal women were not associated with POAG risk; however, a trend of higher testosterone levels being associated with higher POAG risk and higher IOP at diagnosis was observed and needs confirmation.

Association between plasma phospholipid omega-3 polyunsaturated fatty acids and type 2 diabetes is sex dependent: The Hunter Community Study

BACKGROUND & AIMS

Chronic inflammation drives the development of insulin resistance and type 2 diabetes. Long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) eicosapentaenoic acid (EPA, c20:5n-3) and docosahexaenoic acid (DHA, c22:6n-3) may protect against type 2 diabetes development. The aim of this current study is to determine whether LCn-3PUFA status is associated with type 2 diabetes in the Hunter Community Study.

METHODS

Men and women aged 55-85 years were randomly selected from the electoral roll and invited to participate. Participants were included in the current study if they had plasma phospholipid fatty acid composition data available and diabetes status could be determined. LCn-3PUFA status was determined by fatty acid composition of plasma phospholipids (EPA + DHA, %,w/w). Diabetes was determined according to World Health Organisation criteria. Insulin was measured in n = 251 participants and HOMA-IR calculated.

RESULTS

In total, n = 2092 (diabetes: n = 249) participants were included. After adjusting for confounders of diabetes, LCn-3PUFA status was inversely associated with diabetes in overweight/obese females (OR [95%CI]: 0.90 [0.80, 1.00], p = 0.045) but not males (p-interaction_sex = 0.041). Overweight/obese females with diabetes had significantly lower levels of DHA than those without diabetes (mean difference [95%CI]: -0.53 [-0.87, -0.20], p = 0.002), with no difference in EPA. LCn-3PUFA was inversely associated with HOMA-IR (r = -0.175, p = 0.005).

CONCLUSIONS

This study provides further evidence of a sex-dependent association between LCn-3PUFA and type 2 diabetes. Causal pathways between LCn-3PUFA and type 2 diabetes merits delineation.

Hyperostosis frontalis interna in ancient populations from the Carpathian Basin - A possible relationship between lifestyle and risk of development

OBJECTIVE

The prevalence of hyperostosis frontalis interna (HFI) was examined in different periods of the Carpathian Basin from 4900 BCE to 17th century AD. The study seeks to evaluate temporal changes in HFI and the possible impact of lifestyle on it.

MATERIALS

The studied material consisted of 4668 crania from Hungary and Serbia.

METHODS

The crania were analyzed employing macroscopic and endoscopic examination.

RESULTS

In historic periods, sex and age played a pivotal role in HFI development. Among predominantly pastoralist populations of the 5th-8th and 10th centuries, prevalence of HFI was considerably higher than in the medieval populations of the 9th-17th centuries.

CONCLUSIONS

In addition to age and sex, other factors could be implicated in HFI development. The physiological effects of the pastoralist lifestyle and diet on insulin regulation could explain the increased risk of developing HFI in the 5th-8th and 10th-century populations.

SIGNIFICANCE

The study provides the first comprehensive dataset of HFI from different archaeological periods from the Carpathian Basin. It has implications for lifestyle and risk of HFI development in past populations.

LIMITATIONS

The archaeological periods are not equally represented.

SUGGESTIONS FOR FURTHER RESEARCH

In order to better understand the etiology of HFI, lifestyle factors can be used to elucidate the risk of developing HFI in ancient populations.

Multiple Mechanisms Linking Type 2 Diabetes and Alzheimer's Disease: Testosterone as a Modifier

Evidence in support of links between type-2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) has increased considerably in recent years. AD pathological hallmarks include the accumulation of extracellular amyloid-β (Aβ) and intracellular hyperphosphorylated tau in the brain, which are hypothesized to promote inflammation, oxidative stress, and neuronal loss. T2DM exhibits many AD pathological features, including reduced brain insulin uptake, lipid dysregulation, inflammation, oxidative stress, and depression; T2DM has also been shown to increase AD risk, and with increasing age, the prevalence of both conditions increases. In addition, amylin deposition in the pancreas is more common in AD than in normal aging, and although there is no significant increase in cerebral Aβ deposition in T2DM, the extent of Aβ accumulation in AD correlates with T2DM duration. Given these similarities and correlations, there may be common underlying mechanism(s) that predispose to both T2DM and AD. In other studies, an age-related gradual loss of testosterone and an increase in testosterone resistance has been shown in men; low testosterone levels can also occur in women. In this review, we focus on the evidence for low testosterone levels contributing to an increased risk of T2DM and AD, and the potential of testosterone treatment in reducing this risk in both men and women. However, such testosterone treatment may need to be long-term, and would need regular monitoring to maintain testosterone at physiological levels. It is possible that a combination of testosterone therapy together with a healthy lifestyle approach, including improved diet and exercise, may significantly reduce AD risk.

Testosterone a key factor in gender related metabolic syndrome

Metabolic syndrome (MetS) is highly correlated with cardiovascular diseases. Although an excess of body fat is a determinant factor for MetS development, a reduced level of testosterone plays a fundamental role in its regulation. Low testosterone level is highly related to insulin resistance, visceral obesity and MetS. We have searched in Pubmed clinical trial with the password: testosterone and insulin resistance, and testosterone and MetS. We found 19 studies on the correlation between testosterone level with insulin resistance and 18 on the effect of testosterone therapy on MetS. A high correlation between low testosterone and insulin resistance has been found in men, but not in women. Testosterone administration in hypogonadal men improved MetS and reduced the mortality risk. Androgen and oestrogen receptors are expressed in adipocytes, muscle and liver tissue, and their activation is necessary to improve metabolic control. Normalization of testosterone level should be the primary treatment in men, along with caloric restriction and physical exercise. These findings come mainly from correlative data, and there remains a need for randomized trials to strengthen this evidence. This review will consider the effects of testosterone on the regulation and development of MetS in men and women.

Rice consumption, incidence of chronic diseases and risk of mortality: meta-analysis of cohort studies

OBJECTIVE

Findings from cohort studies investigating the association between rice consumption and risk of chronic diseases or mortality have been inconsistent. We performed a comprehensive systematic review and meta-analysis on all published cohort studies examining white rice consumption in relation to incidence of chronic diseases or risk of mortality.

DESIGN

A systematic literature search of MEDLINE, Embase, Cochrane review, Google Scholar and Scopus databases for relevant cohort studies published until July 2014. For systematic review, we found nineteen studies examining the association between rice intake and risk of chronic diseases (obesity, hypertension, metabolic syndrome, diabetes, CVD and cancers) or mortality. Cohort studies which reported relative risk (RR) or odds ratio for highest v. lowest intake of rice and chronic diseases or mortality were included in the meta-analysis.

RESULTS

In a meta-analysis on seventeen risk estimates for highest v. lowest category of rice intake, provided from twelve studies, we found a trend towards a positive association (RR; 95 % CI) between rice consumption and risk of all chronic diseases (1·11; 0·96, 1·29); however, significant between-study heterogeneity was found (I 2=70·3 %, P<0·001). Stratified analysis by gender showed a significant positive association between rice consumption and risk of chronic diseases in women (1·40; 1·13, 1·73), but not in men (0·95; 0·72, 1·24). Combining ten effect sizes from five studies showed that high consumption of rice was not significantly associated with mortality (0·97; 0·88, 1·06). Subgroup analysis by gender indicated an inverse association between rice consumption and mortality in men (0·87; 0·81, 0·94), but a trend towards a positive association in women (1·08; 0·97, 1·19).

CONCLUSIONS

Although white rice consumption was not found to be associated with individual chronic conditions, we observed a positive association between white rice intake and risk of all overall chronic diseases in women. High rice consumption was related to a modest reduction in risk of mortality in men but not in women. Further studies of these relationships, in different populations, are needed.

Role of adiponectin in mediating the association of osteocalcin with insulin resistance and type 2 diabetes: a cross sectional study in pre- and post-menopausal women

OBJECTIVE

To analyse the association of osteocalcin with insulin resistance and type 2 diabetes and assess the role of adiponectin in these relationships.

METHODS

This study comprised 98 newly diagnosed type 2 diabetic women (51 pre-menopausal and 47 post-menopausal) and 102 age and BMI matched controls (53 pre-menopausal and 49 post-menopausal). Insulin resistance was calculated by homeostasis model assessment-insulin resistance (HOMA-IR).

RESULTS

Osteocalcin was significantly positively correlated with adiponectin in both pre-menopausal (p = 0.0026) and post-menopausal diabetic women (p = 0.0357). Significant negative association between osteocalcin and HOMA-IR was observed only in pre-menopausal diabetic women (p = 0.0019), but the association was partially reduced (p = 0.0219) after additional adjustment for adiponectin. Adiponectin slightly attenuated the inverse association between osteocalcin and presence of type 2 diabetes in both pre- and post-menopausal women.

CONCLUSION

The protective action of osteocalcin against the development of insulin resistance and type 2 diabetes in women may be partially mediated through up-regulation of adiponectin secretion.