Salt sensitivity correlates positively with insulin sensitivity in healthy volunteers

Abstract

In healthy normotensive subjects who display a wide range of insulin sensitivity, as measured with the euglycaemic clamp technique, salt sensitivity correlates positively with insulin sensitivity and HDL-cholesterol, but not with the other characteristics of the insulin resistance syndrome.

Increased insulin resistance in salt sensitive essential hypertension

“…7 These results have recently been confirmed by another group in 47 normotensive subjects with a normal oral glucose tolerance test, who underwent the euglycaemic hyperinsulinaemic clamp. 8 On the contrary, in 18 normotensive obese subjects, Egan et al 12 did not find significant differences between salt sensitive and salt resistant subjects in the area under the curve of insulin after an oral glucose tolerance test. Moreover, on studying 28 normotensive subjects with a positive family history of hypertension, Mellander et al 13 did not find any relationship between the blood pressure response to high salt intake and insulin sensitivity, measured by the euglycaemic clamp technique.…”

“…Several studies [5][6][7][8][9][10][11][12][13][14][15] have addressed the issue of the possible relationship between salt sensitivity and both insulin resistance and other glucose metabolic parameters, with some controversial results. In normotensive subjects, Sharma et al 6,7 found a direct relationship between salt sensitivity and insulin response to an oral glucose tolerance test, 6 a finding confirmed 2 years after measuring insulin sensitivity by the insulin suppression test.…”

“…3,4 Bigazzi et al 5 demonstrated higher levels of insulin, total cholesterol, low-density lipoprotein (LDL)-cholesterol and urinary albumin excretion in salt sensitive hypertensives compared with salt resistant patients, suggesting that insulin resistance could be responsible for this atherogenic cluster. Studies of the association between salt sensitivity and insulin resistance have yielded contradictory results, in both normotensive [6][7][8] and in hypertensive sub-characteristics, fasting serum insulin, fasting serum glucose, glycosilated haemoglobin, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, uric acid and microalbuminuria. Salt sensitive patients exhibited a reduced insulin sensitivity index compared with salt resistant patients (1.7 ؎ 1.1 vs 3.5 ؎ 1.2 mg/kg/min; P ‫؍‬ 0.009).…”

“…Although only one author 9 used the less time-consuming intravenous method to determine blood pressure sensitivity to salt intake, diagnostic criteria were completely different among all studies that used oral salt load. There is also a high heterogeneity in the methodology applied to measure insulin sensitivity, and only three studies used the euglycaemic hyperinsulinaemic clamp technique, 8,9,13 considered the gold standard method. 16 Another limitation is the inclusion of some effect modifiers in the studied groups.…”

Serum- and Glucocorticoid-Inducible Kinase 1 Mediates Salt Sensitivity of Glucose Tolerance

“…E xcessive salt intake may impede cellular glucose uptake in peripheral tissues and, thus, lead to delayed decrease of plasma glucose concentrations following a glucose load (1)(2)(3)(4)(5). Mechanisms accounting for the salt sensitivity of peripheral glucose uptake have remained ill defined.…”