Miwa Ryo

Adiponectin Replenishment Ameliorates Obesity-Related Hypertension

Patients with obesity are susceptible to hypertension. We have reported that the plasma adiponectin levels are decreased in obesity and that adiponectin has many defensive properties against obesity-related diseases, such as type 2 diabetes and coronary artery disease. The aim of this study was to determine the relationship between adiponectin and hypertension in mice. We measured blood pressure and heart rate directly by a catheter in the carotid artery and indirectly by automatic sphygmomanometer at the tail artery. Obese KKAy mice had significantly lower plasma adiponectin levels and higher systolic blood pressure than control C57BL/6J mice at 21 weeks of age. Adenovirus-delivered adiponectin significantly decreased blood pressure in KKAy mice. The direct role of adiponectin on blood pressure regulation under insulin resistance–free state was investigated in adiponectin-knockout (KO) mice. Adiponectin KO mice developed hypertension when maintained on a high-salt diet (8% NaCl) without insulin resistance. The hypertension of salt-fed adiponectin KO mice was associated with reduced mRNA levels of endothelial NO synthase (eNOS) and prostaglandin I2 synthase in aorta and low metabolite levels of endothelial NO synthase and prostaglandin I2 synthase in plasma. Adiponectin therapy lowered the elevated blood pressure and corrected the above mRNA levels to those of the wild type. Our results suggest that hypoadiponectinemia contributes to the development of obesity-related hypertension, at least in part, directly, in addition to its effect via insulin resistance, and that adiponectin therapy can be potentially useful for hypertension in patients with the metabolic syndrome.

Changes in Serum Adiponectin Concentrations Correlate With Changes in BMI, Waist Circumference, and Estimated Visceral Fat Area in Middle-Aged General Population

Adiponectin was identified as an adipocytokine in the human adipose tissue cDNA library. It has antiatherosclerotic and antidiabetic properties in experimental studies, and its blood levels are low in obesity, diabetes, cardiovascular diseases, and metabolic syndrome. Several studies have reported that weight reduction in massively obese subjects is associated with a rise in serum adiponectin (APN) concentration (1–3). However, the relationship between changes in APN and BMI, waist circumference (WC), and visceral fat accumulation (VFA) in general population has not been reported. The present study investigated 1-year change in APN (ΔAPN) in relation to changes in BMI (ΔBMI), WC …

Visceral Obesity and Hypoadiponectinemia are Significant Determinants of Hepatic Dysfunction: An Epidemiologic Study of 3827 Japanese Subjects

Background and Aim Adiponectin is an anti-inflammatory and insulin-sensitizing adipocytokine, and its serum concentrations are reduced in obesity with visceral fat accumulation. Visceral fat accumulation is an independent determinant of elevated serum liver enzymes. Hypoadiponectinemia plays important roles in the clinical progression of nonalcoholic steatohepatitis. The aim of this study was to evaluate the relation between visceral fat area (VFA), serum adiponectin concentration, and biochemical liver tests, such as aspartate aminotransferase, alanine aminotransferase (ALT), and γ-glutamyltransferase (GGT) in normal subjects. Methods The study group comprised 3827 Japanese subjects [mean age±SD; 47.6±10.7 y: 2854 males (48.4±10.7 y), 973 females (45.3±10.1 y)], who underwent annual health checkup in 2004. In addition to parameters measured in the annual health checkup, VFA and serum adiponectin concentration were measured by the bioelectrical impedance analysis method and a latex particle-enhanced turbidimetric assay system, respectively. Results Pearsons correlation analysis showed a significant correlation between VFA and the levels of the above 3 liver enzymes in both sexes, and a significant negative correlation between adiponectin and all biochemical liver tests in men and with ALT and GGT in women. Stepwise multiple regression analysis showed that VFA was a significant determinant of serum liver tests in both sexes. Moreover, serum adiponectin concentration significantly and negatively influenced male ALT and GGT and female GGT. Conclusions Both visceral obesity and hypoadiponectinemia are significant determinants of subtle and asymptomatic hepatic dysfunction in normal Japanese subjects.

Insulin-secretion capacity in normal glucose tolerance, impaired glucose tolerance, and diabetes in obese and non-obese Japanese patients.

Aims/Introduction:  Pronounced reduction of insulin secretion in response to a rise in glucose level has been reported in Japanese patients compared with Caucasian patients, but the mean body mass index (BMI) is also lower in Japanese patients. As BMI is a determinant of insulin secretion, we examined insulin‐secretion capacity in obese and non‐obese Japanese patients.

Predictors of deterioration of glucose tolerance and effects of lifestyle intervention aimed at reducing visceral fat in normal glucose tolerance subjects with abdominal obesity.

Aims/Introduction:  The aim of the present study was to determine the predictors of deterioration of glucose tolerance in individuals with normal glucose tolerance (NGT) and abdominal obesity, and whether a lifestyle intervention to reduce visceral fat is effective in these individuals.

Short-term intervention reduces bioelectrical impedance analysis-measured visceral fat in type 2 diabetes mellitus.

In 25 patients with Type 2 diabetes mellitus, the short-term in-hospital calorie restriction combined with moderate exercise reduced visceral fat. The reduction of visceral fat can improve metabolic cardiovascular risk factors, while the reductions in body weight and waist circumference were small and reduction in subcutaneous fat was not significant.