Association Of Adiponectin Concentration With Hypertension And Insulin Resistance

Background: Adipose tissue was once thought to be simply a depot for fuel storage in the form of triglyceride. However, it is now known that adipocytes secretes many biologically active molecules such as tumor necrosis factor-α, leptin, adiponectin, resistance and plasminogen-activator inhibitor type 1. Adiponectin is one of the key molecules in the metabolic syndrome, and its concentration is decreased in obesity, insulin resistance, type- II diabetes, and coronary artery disease. Adiponectin can reduce triglyceride accumulation in skeletal muscle; enhance insulin sensitivity; modulate the endothelial inflammatory response and prevent atherosclerosis. Even though an association between hypertension and serum adiponectin concentration has been reported by several groups using a small number of subjects, the results are inconsistent. Mallamaci et al reported an increased plasma adiponectin concentration in hypertensive patients with renal dysfunction, but Adamczak et al reported decreased adiponectin in hypertensive subjects. Maruyoshi Y showed that hypoadiponectinemia is an independent risk factor. Furuhashi et al reported that only hypertensive patients with insulin resistance showed lower adiponectin concentration. It has been shown that approximately 40% of essential hypertension is insulin resistance. Insulin resistance and accompanying hyperinsulinemia have been linked to the onset and progression of hypertension and atherosclerosis.But the hypoadiponectinemia in hypertension patients is the result of an increase in blood pressure itself or the accompanying condition insulin resistance was not clear. So we designed a study to investigate the association of hypoadiponectinemia, hypertension and insulin resistance. Objective: Plasma adiponectin concentrations in the four groups were compared in order to investigate the association of adiponectin concentration with hypertension and insulin resistance.Methods: A total of 180 diagnosed cases of essential hypertension (EHT) and 180 normotensive subjects (NT) were enrolled in this study to test the relationship of hypertension and insulin resistance. Then we selected total 170 subjets which had been taking no medicine or had stopped taking all drugs that may affect blood pressure, insulin, glucose, blood fat value at least 3 months before the start of the study. There were 41 essential hypertensive patients with insulin resistance (EHT-R), 47 essential hypertensive patients without insulin resistance (EHT-N), 41 normotensive subjects with insulin resistance (NT-R) and 41 normotensive subjects without insulin resistance (NT-N) were enrolled in our research. Plasma adiponectin concentrations in the four groups were compared in order to approach the association of adiponectin concentration with hypertension and insulin resistance.Results:1. The proportion of hypertension in female subjects was lower than male subjects. Multiple regression analysis revealed that age, sex, BMI, and HOMA-IR independently affected the risk for hypertension of the total subjects.2. In the 170 subjects, there was no significantly difference of adiponectin concentration in the four groups.3. Adiponectin concentrations in NT-R male group were lower than that of NT-N male group; in EHT-N male group, the adiponectin concentrations decreased compared to NT-N male subjects. No interaction was detected significantly between the insulin resistance and hypertension to adiponectin concentration after adjustment for BMI and HDL-C value.4. In the female subjects, there was no significantly difference of adiponectin concentration in the four groups (F=0.818, P=0.489). The adiponectin concentrations in NT-N female groups were lowest.Conclusion: The results demonstrated that age, sex, BMI, and HOMA-IR independently affected the risk for hypertension of the subjects; insulin resistance and hypertension were independent factors for hypoadiponectinemia in the male subjects.Innovation: In our study, we revealed that insulin resistance and hypertension were independent factors for hypoadiponectinemia, adiponectin maybe the key factor which connected the insulin resisitance and hypertension.