Dehydroepiandrosterone-enhanced dual specificity protein phosphatase (DDSP) prevents diet-induced and genetic obesity

Low serum albumin, aspartate aminotransferase, and body mass are risk factors for frailty in elderly people with diabetes-a cross-sectional study

Background

Frailty is broadly characterized by vulnerability and decline in physical, mental and social activities and is more common in elderly patients with type 2 diabetes mellitus (T2DM). Frailty is closely associated with nutrition, muscle strength, inflammation, and hormones etc. In hormones, dehydroepiandrosterone sulfate (DHEA-S) and cortisol are suggested to be such candidates affecting frailty. Little investigation has been performed using a wider range of measures of frailty to clarify risk factors for frailty including the above two hormones.

Methods

We performed a cross-sectional study to investigate the risk factors for frailty in elderly T2DM patients (n = 148; ≥65 years), using a broad assessment, the clinical frailty scale. We compared parameters between the non-frail and frail groups using the unpaired t and Mann-Whitney U tests. The Jonckheere-Therpstra test was used to identify relationships with the severity of frailty, and risk factors were identified using binary regression analysis.

Results

Simple regression analysis identified a number of significant risk factors for frailty, including DHEAS < 70 μg/dL and cortisol/DHEA-S ratio ≥ 0.2. Multiple regression analysis showed that low albumin (< 4.0 g/dl) (odds ratio [OR] = 5.79, p < 0.001), low aspartate aminotransferase (AST) activity (< 25 IU/L) (OR = 4.34, p = 0.009), and low body mass (BM) (< 53 kg) (OR = 3.85, p = 0.012) were independent risk factors for frailty. A significant decrease in DHEA-S and a significant increase in the cortisol/DHEA-S ratio occurred alongside increases in the severity of frailty. DHEA-S concentration positively correlated with both serum albumin and BM.

Conclusions

Hypoalbuminemia, low AST, and low BM are independent risk factors for frailty in elderly T2DM patients, strongly implying relative malnutrition in these frail patients. DHEA-S may be important for the maintenance of liver function and BM. A decrease in DHEA-S and an increase in the cortisol/DHEAS ratio may be involved in the mechanism of the effect of malnutrition in elderly T2DM patients.

A High Serum Cortisol/DHEA-S Ratio Is a Risk Factor for Sarcopenia in Elderly Diabetic Patients

Context

Elderly patients with type 2 diabetes mellitus (T2DM) have a high prevalence of frailty and/or sarcopenia. Sarcopenia is thought to be related to discordant secretions of the adrenal hormones cortisol and dehydroepiandrosterone (DHEA), as well as the sulfate ester of DHEA (DHEA-S). The current study sought to evaluate the risk factors for sarcopenia in elderly patients with T2DM.

Design and Patients

We enrolled 108 consecutive elderly patients aged ≥65 years with T2DM (mean age, 76.2 ± 7.3 years; 43.5% males). Sarcopenia was assessed and diagnosed based on the Asian version of the diagnostic criteria regarding muscular strength, physical function, and muscle mass. We assessed various physical parameters, blood tests, and atherosclerosis markers and statistically determined the risk factors for sarcopenia.

Results

Multiple regression analysis showed that the independent risk factors for sarcopenia were a serum cortisol/DHEA-S ratio ≥0.2, diastolic blood pressure <70 mm Hg, Hb concentration <13 g/dL, and an ankle brachial index <1.0. The strongest risk factor for sarcopenia was a serum cortisol/DHEA-S ratio ≥0.2. An increase in the serum cortisol/DHEA-S ratio reflected higher cortisol values and lower DHEA-S values in patients with sarcopenia compared with those in nonsarcopenic patients. The concentrations of cortisol and DHEA-S, as well as the cortisol/DHEA-S ratio, changed in accordance with the severity of sarcopenia.

Conclusions

A relative increase in cortisol may reflect the presence of stress and stimulate muscle catabolism, whereas a relative decrease in DHEA-S may cause a decrease in the anabolic action of DHEA on muscle; the combination of these factors may lead to sarcopenia.

Effect of Dehydroepiandrosterone (DHEA) on Diabetes Mellitus and Obesity

Type 2 diabetes is a metabolic disorder that is characterized by an impaired capacity to secrete insulin, insulin resistance, or both. Dehydroepiandrosterone (DHEA), a steroid hormone produced by the adrenal cortex, has been reported to have beneficial effects on diabetes mellitus and obesity in animal models. DHEA and DHEA-sulfate (DHEA-S) have been reported to increase not only insulin secretion of the pancreas but also insulin sensitivity of the liver, adipose tissue, and muscle. We investigated the effects of DHEA on glucose metabolism in animal models and reported decrease of liver gluconeogenesis. Recently, we reported the effect of DHEA on the liver and muscle by using insulin-stimulated insulin receptor substrate 1 and 2 (IRS1 and IRS2)-deficient mice. DHEA increased Akt phosphorylation in the liver of C57BL6 IRS1- and IRS2-deficient mice fed with a high-fat diet (HFD), which suggests that the increase in DHEA-induced Akt signaling is sufficient in the presence of IRS1 or IRS2. In addition, other studies have also reported the effect of DHEA on diabetes mellitus in the liver, muscle, adipose tissue, and pancreatic β-cell and its effect on obesity in animal models. A meta-analysis in elderly men and women has found that DHEA supplementation has no effects on blood glucose levels. However, DHEA supplementation to patients with type 2 diabetes has not been fully elucidated. Therefore, further studies are needed to provide greater insight into the effect of DHEA on diabetes and obesity in animal and human models.

Dehydroepiandrosterone and Experimental Osteoarthritis

Despite an increased understanding of the pathogenesis of osteoarthritis (OA) and the availability of a number of drugs designed to ameliorate its symptoms, a successful disease-modifying therapy remains elusive. Recent lines of evidence suggest that dehydroepiandrosterone (DHEA), a 19-carbon steroid hormone classified as an adrenal androgen, exerts a chondroprotective effect in OA patients, and it has been proven to be an effective DMOAD candidate that slows OA progression. However, the exact mechanisms underlying its anti-OA effect is largely unknown. This review summarizes emerging observations from studies of cell biology, preclinical animal studies, and preliminary clinical trials and describes the findings of investigations on this topic to develop an initial blueprint of the mechanisms by which DHEA slows OA progression. Presently, studies on DMOADs are increasing in importance but have met limited success. Encouragingly, the current data on DHEA are promising and may prove that DHEA-based treatment is efficacious for preventing and slowing human OA progression.

Pharmacological targeting of glucose-6-phosphate dehydrogenase in human erythrocytes by Bay 11-7082, parthenolide and dimethyl fumarate

In mature erythrocytes, glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) yield NADPH, a crucial cofactor of the enzyme glutathione reductase (GR) converting glutathione disulfide (GSSG) into its reduced state (GSH). GSH is essential for detoxification processes in and survival of erythrocytes. We explored whether the anti-inflammatory compounds Bay 11–7082, parthenolide and dimethyl fumarate (DMF) were able to completely deplete a common target (GSH), and to impair the function of upstream enzymes of GSH recycling and replenishment. Treatment of erythrocytes with Bay 11–7082, parthenolide or DMF led to concentration-dependent eryptosis resulting from complete depletion of GSH. GSH depletion was due to strong inhibition of G6PDH activity. Bay 11–7082 and DMF, but not parthenolide, were able to inhibit the GR activity. This approach “Inhibitors, Detection of their common target that is completely depleted or inactivated when pharmacologically relevant concentrations of each single inhibitor are applied, Subsequent functional analysis of upstream enzymes for this target” (IDS), can be applied to a broad range of inhibitors and cell types according to the selected target. The specific G6PDH inhibitory effect of these compounds may be exploited for the treatment of human diseases with high NADPH and GSH consumption rates, including malaria, trypanosomiasis, cancer or obesity.