High Sodium Intake Enhances Insulin‐stimulated Glucose Uptake in Rat Epididymal Adipose Tissue

Abstract

Objective: This study investigated the effect of different sodium content diets on rat adipose tissue carbohydrate metabolism and insulin sensitivity. Methods and Procedures: Male Wistar rats were fed on normal-(0.5% Na + ; NS), high-(3.12% Na + ; HS), or low-sodium (0.06% Na + ; LS) diets for 3, 6, and 9 weeks after weaning. Blood pressure (BP) was measured using a computerized tail-cuff system. An intravenous insulin tolerance test (ivITT) was performed in fasted animals. At the end of each period, rats were killed and blood samples were collected for glucose and insulin determinations. The white adipose tissue (WAT) from abdominal and inguinal subcutaneous (SC) and periepididymal (PE) depots were weighed and processed for adipocyte isolation and measurement of in vitro rates of insulin-stimulated 2-deoxy-d-[ Results: After 6 weeks, HS diet significantly increased the BP, SC and PE WAT masses, PE adipocyte size, and plasma insulin concentration. The sodium dietary content did not influence the whole-body insulin sensitivity. A higher half-maximal effective insulin concentration (EC 50 ) from the dose-response curve of 2DGU and an increase in the insulin-stimulated glucose oxidation rate were observed in the isolated PE adipocytes from HS rats. Discussion: The chronic salt overload enhanced the adipocyte insulin sensitivity for glucose uptake and the insulin-induced glucose metabolization, contributing to promote adipocyte hypertrophy and increase the mass of several adipose depots, particularly the PE fat pad.

Dietary Sodium, Adiposity, and Inflammation in Healthy Adolescents

“…31,32 Second, independent of energy intake, chronic salt overload induced adipocyte hypertrophy and increased mass of adipose depots and high plasma leptin concentration by enhancing the adipocyte insulin sensitivity for glucose uptake, the insulin-induced glucose metabolism, and lipogenic capacity of white adipose tissue in rats. 1,2,33 We also found that sodium intake was positively and independently associated with increased circulating levels of leptin. Leptin is one of the most important adipokines secreted by fat cells, with a variety of physiologic roles related to the control of metabolism, maintenance of energy homeostasis and body weight, inflammatory response, and urinary sodium excretion.…”

Iron Excess Disturbs Metabolic Status and Relative Gonad Mass in Rats on High Fat, Fructose, and Salt Diets

“…In short-term (4 weeks) human studies, high fructose diets have also not affected insulin sensitivity [20]. It has been observed that 6 weeks of high sodium diet can significantly increase blood pressure and insulin level in serum in rats, but the diets employed in those experiments contained more than twice the sodium used in this study [21]. …”

Identifying predictors of high sodium excretion in patients with heart failure: A mixed effect analysis of longitudinal data

“…51 Song and colleagues report a direct effect between sodium intake and risk of being overweight in humans, after adjusting for energy, water, and soda consumption; 31 however, their study sample did not include patients with heart failure, hypertension or diabetes. The relationship between obesity and sodium consumption is consistent with results of our previous study in which we found that patients with heart failure who were overweight had a four-fold increased odds of consuming more than 3000 mg of sodium per day.…”