Castration and diabetes

Testosterone deficiency induces markedly decreased serum triglycerides, increased small dense LDL, and hepatic steatosis mediated by dysregulation of lipid assembly and secretion in mice fed a high-fat diet

OBJECTIVE

Although low serum testosterone (T) is associated with metabolic disorders, the mechanism of this association is unclear. The objective of the present study was to investigate the combined effects of T deficiency and a high-fat diet (HFD) on hepatic lipid homeostasis in mice.

MATERIALS/METHODS

Orchiectomized (ORX) mice and sham-operated (SHAM) mice were randomly divided into five groups: SHAM mice fed a standard diet (SD), SHAM mice fed HFD, ORX mice fed SD, ORX mice fed HFD, and ORX mice fed HFD with T supplementation. After 4weeks of treatment, we investigated the synthesis and secretion of lipids in the liver and detailed serum lipoprotein profiles in each group.

RESULTS

ORX mice fed HFD showed increased hepatic steatosis, markedly decreased serum triglyceride (TG) and TG-VLDL content, and increased serum very small-LDL content. Gene expression analysis revealed that ORX mice fed HFD showed significantly decreased expression of microsomal triglyceride transfer protein, lipin-1, peroxisome proliferator-activated receptor (PPAR)-α and PPAR-γ coactivator 1-α, and significantly increased sterol regulatory element-binding protein-1, diacylglycerol acyltransferase-2 and fatty acid synthase. Reduction of hepatic AMPK phosphorylation was observed in ORX mice fed HFD. These perturbations in ORX mice fed HFD were normalized to the levels of SHAM mice fed HFD by T supplementation.

CONCLUSION

T deficiency is associated with failure of lipid homeostasis mediated by altered expression of genes involved in hepatic assembly and secretion of lipids.

Association between Relative Hypogonadism and Metabolic Syndrome in Newly Diagnosed Adult Male Patients with Impaired Glucose Tolerance or Type 2 Diabetes Mellitus

Sex steroid hormones are known to be important regulators of the lipid and glucose metabolism. Lower levels of testosterone (T) or sex hormone-binding globulin (SHBG) have been reported in men with type 2 diabetes. On the other hand, the relationship between relative hypogonadism and metabolic syndrome has not yet to be thoroughly studied. Ninety-eight Japanese adult (age 20-64) male patients with impaired glucose tolerance (IGT) or type 2 diabetes mellitus were divided into either an metabolic syndrome group (n = 42) or a non- metabolic syndrome (n = 56) group according to the definition of metabolic syndrome from WHO, or into three tertiles according to their sex hormone index level. The metabolic syndrome group had a significantly lower T/estradiol (E(2)) and SHBG level (p < 0.01). The age and subcutaneous fat surface area (SFA) were significantly different within the tertiles in SHBG and T/E(2). Logistic regression analyses were performed to investigate the association between the sex steroid hormone index level and the incidence of metabolic syndrome. Regarding the highest tertiles as a criterion, lower SHBG, T/E(2) or free T/E(2) had a higher odds ratio of prevalence of metabolic syndrome even after adjusting for age and SFA. Relative hypogonadism was strongly associated with the prevalence of metabolic syndrome in Japanese adult men who were newly diagnosed to have IGT or type 2 diabetes.

Parenteral Estrogens for Prostate Cancer: Can a New Route of Administration Overcome Old Toxicities?

Androgen deprivation therapy (ADT) is the mainstay of management of advanced-stage prostate cancer and recently has been shown to improve survival when administered in earlier stages of the disease. The oncologic benefits of ADT might be partially offset, however, by a reduction in quality of life because of adverse effects. In addition to the well-recognized adverse consequences of ADT, recent evidence suggests that ADT is associated with dyslipidemia, impaired glucose metabolism, adverse body compositional changes, and osteoporosis. Therefore, there is a pressing need to develop less toxic forms of ADT. A novel approach to this problem is the use of estrogen to induce androgen suppression. Whereas oral estrogen therapy is known to be associated with thromboembolic complications, studies of parenteral estrogen in men with prostate cancer suggest that the use of parenteral estrogen achieves target androgen suppression, does not adversely affect prothrombotic protein levels, and is not associated with adverse metabolic, skeletal, and body compositional changes when compared with conventional ADT. Herein, we review the data for parenteral estrogen use in prostate cancer, the antineoplastic mechanisms of action of estrogen in prostate cancer, the potential advantages of parenteral estrogen compared with conventional ADT, and the remaining barriers in the use of parenteral estrogen in prostate cancer.

Serum dehydroepiandrosterone sulfate concentration and carotid atherosclerosis in men with type 2 diabetes

Decreased serum dehydroepiandrosterone (DHEA) concentrations may be associated with an increased risk of cardiovascular disease (CVD) in men. We evaluated relationships between serum DHEA sulfate (DHEA-S) concentration and carotid atherosclerosis, as well as major cardiovascular risk factors, in men with type 2 diabetes. Serum DHEA-S concentrations were measured in 206 consecutive men with type 2 diabetes. Relationships were analyzed between serum DHEA-S concentration and carotid atherosclerosis, determined by ultrasonographically evaluated intima-media thickness (IMT) and plaque score (PS), as well as major cardiovascular risk factors, including age, blood pressure, and lipid concentrations. Negative correlations were found between DHEA-S concentration and IMT (r = -0.298, P < 0.0001) and between DHEA-S concentration and PS (r = -0.308, P < 0.0001). IMT and PS were significantly greater in patients with lower concentrations of DHEA-S (<1000 ng/ml) than in patients with higher concentrations of DHEA-S (1.07+/-0.30 mm versus 0.91+/-0.19 mm, P < 0.0001, and 5.5+/-4.2 versus 3.1+/-3.4, P < 0.0001, respectively). A negative correlation was found between serum DHEA-S concentration and age (r = -0.488, P < 0.0001). Multiple regression analysis demonstrated that serum DHEA-S concentration was an independent determinant of IMT (beta = -0.289, P < 0.0001) and of PS (beta = -0.301, P < 0.0001). In conclusion, serum DHEA-S concentration is negatively associated with carotid atherosclerosis determined by ultrasonographically evaluated IMT and PS in men with type 2 diabetes.

Association between serum testosterone concentration and carotid atherosclerosis in men with type 2 diabetes

OBJECTIVE

There is evidence to suggest that low concentrations of testosterone are associated with an increased risk of cardiovascular disease in men. The aim of this study was to evaluate the relationship between serum testosterone concentration and carotid atherosclerosis as well as major cardiovascular risk factors in men with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Serum free and total testosterone concentrations were measured in 253 consecutive men with type 2 diabetes. The relationships between serum testosterone concentration and carotid atherosclerosis, determined by ultrasonographically evaluated intima-media thickness (IMT) and plaque score (PS) in a subgroup of 154 diabetic patients, as well as major cardiovascular risk factors, including age, blood pressure, and lipid concentrations, were evaluated.

RESULTS

Inverse correlations were found between free testosterone (F-tes) concentration and IMT (r = -0.206, P = 0.0103) and between F-tes concentration and PS (r = -0.334, P < 0.001). The IMT and PS were significantly greater in patients with lower concentrations of F-tes (<10 pg/ml) than in patients with higher concentrations of F-tes (1.01 +/- 0.29 vs. 0.91 +/- 0.26 mm, P = 0.038; 4.5 +/- 3.8 vs. 2.4 +/- 3.2, P = 0.0003; respectively). An inverse correlation was found between serum F-tes concentration and age (r = -0.420, P < 0.0001). A positive correlation was found between serum F-tes and total cholesterol concentrations (r = 0.145, P = 0.0238).

CONCLUSIONS

Serum F-tes concentration is inversely associated with carotid atherosclerosis determined by ultrasonographically evaluated IMT and PS in men with type 2 diabetes.

The metabolic syndrome in long-term cancer survivors, an important target for secondary preventive measures

With increasing numbers of cancer survivors, attention has been drawn to long-term complications of curative cancer treatment, including a range of metabolic disorders. These metabolic disorders often resemble the components of the so-called metabolic syndrome, or syndrome X, which is an important risk factor for the development of cardiovascular disease. The mechanisms behind the development of metabolic disorders in cancer survivors have not been fully elucidated. However, association studies in the general population have demonstrated correlations between the components of the metabolic syndrome on the one hand and hormonal deficiencies, hypomagnesaemia, and endothelial dysfunction on the other. These latter disorders are regularly reported following curative cancer treatment and could, therefore, be important aetiologic factors in the development of the metabolic syndrome in cancer survivors. This review discusses data on the associations between the metabolic syndrome and treatment-related complications in cancer survivors and possibilities for preventive measures.