Low daily salt intake is correlated with albuminuria in patients with type 2 diabetes

Abstract

Both high and low salt intakes have been reported to be associated with an increased risk of cardiovascular events. The aim of this study was to investigate the relationship between daily salt intake and albuminuria, a marker of diabetic nephropathy and cardiovascular disease, in patients with type 2 diabetes. We classified 270 patients with type 2 diabetes, who were not receiving antihypertensive medication into four groups according to their daily salt intake (o8, 8-10, 10-12 and 412 g per day). We investigated the relationship between daily salt intake and the logarithm of urinary albumin excretion (UAE). A multivariate linear regression analysis was used to evaluate whether daily salt intake independently correlated with the logarithm of UAE. In addition, we assessed the contribution of the variables, including age, sex, duration of diabetes, body mass index, systolic blood pressure, hemoglobin A 1C , low-density lipoprotein cholesterol, triglycerides, serum creatinine, alcohol intake, smoking status and square of (daily salt intake À10) on albuminuria, defined as a UAE430 mg g À1 of creatinine, using a multiple logistic regression analysis. The logarithm of the UAE was lowest in the third quartile of daily salt intake. The multivariate linear regression analysis demonstrated that the logarithm of the UAE was significantly correlated with the quadratic term of daily salt intake centered at 10 g per day (b ¼ 0.170, P ¼ 0.008). The multivariate logistic regression analysis demonstrated that the odds ratio (95% confidence interval) of albuminuria was 3.996 (1.295-12.327; P ¼ 0.016) in patients whose daily salt intake was less than 8 g per day compared with patients whose daily salt intake was 10-12 g per day. In conclusion, low daily salt intake was correlated with albuminuria in patients with type 2 diabetes, who were not receiving antihypertensive medication.

Renal function in relation to sodium intake: a quantitative review of the literature

“…Seven studies were population based, 10,12,13,[15][16][17][18] and 2 had been conducted in diabetic patients 14,19 or hypertensive subjects. 11,20 Sodium intake was estimated from spot urine samples in 4 studies, 13,16,17,19 from 24-hour urine collections in 5, 10,11,14,15,20 from a food frequency questionnaire in 1, 18 and from dietary recall in 1.…”

“…Of the 247 full-text papers we read, 36 studies, including 73,482 participants, fulfilled the inclusion criteria and provided enough data to be included in at least one meta-analysis. Of these, 11 were crosssectional studies, [10][11][12][13][14][15][16][17][18][19][20] 5 were longitudinal cohort studies, [21][22][23][24][25] and 20 were intervention trials. [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] The weighted means of sodium intake were similar among studies in which consumption was assessed by means of spot urine samples 13,16,17,19 (mean, 156 mmol/d; range, 96-209 mmol/ d) 16,17 and 24-hour urine collections 10,11,14,15,…”

“…11,20 Sodium intake was estimated from spot urine samples in 4 studies, 13,16,17,19 from 24-hour urine collections in 5, 10,11,14,15,20 from a food frequency questionnaire in 1, 18 and from dietary recall in 1. 12 Of the 11 cross-sectional studies, 8 were focused on albumin excretion 12,14,15,19 or the urinary albumin-to-creatinine ratio 13,16-18 as a dichotomous [12][13][14][15][17][18][19] or continuous outcome. 16 Estimated GFR was reported in 6 cross-sectional studies.…”

Dietary Sodium Intake in Patients with Type 2 Diabetes Mellitus

“…The World Health Organization (WHO) [5] and Korean Diabetes Association [6] recommend a sodium intake of <2,000 mg/day. However, the benefits of low dietary sodium intake in patients with T2DM are still unclear, while some studies reported that reduced sodium intake resulted in albuminuria [7], cardiovascular diseases, and mortality [8]. …”

“Slow”ing Cardiovascular Risk in Type 2 Diabetics by Restricting Dietary Salt Intake

“…For example, high salt intake has been reported to promote renal injury in type 2 diabetics, 7 and Suckling et al conducted a meta-analysis concluding that dietary salt restriction attenuated diabetic kidney disease (both type 1 and type 2). 8 However, others reported that when dietary sodium was below 8 g/d, the odds ratio of developing albuminuria was increased 9 and that a reduction in urinary sodium excretion was associated with increased cardiovascular risk and all-cause mortality in type 2 diabetics. 10 The conflicting reports may result from the observational nature of some of the studies, but still leaves a significant gap in knowledge about the role of dietary sodium in cardiovascular risk in type 2 diabetics that could be addressed in a well-controlled clinical study.…”