The association between dietary sodium intake and adiposity, inflammation, and hormone markers: A preliminary study

Abstract

Purpose: Excess intake of sodium is a major diet-related risk factor for human diseases including hypertension and cancer as well as obesity and inflammation. However, findings are still controversial, and evidence is lacking in Koreans. Therefore, for better understanding of the role of dietary sodium intake in disease etiology, this study investigated the effects of dietary sodium intake on adiposity, inflammation, and hormones in Koreans. Methods: A total of 80 males and females joined the study. The general characteristics and dietary intake data were investigated by trained interviewers using a questionnaire and 24-h dietary recall, respectively. For the markers of adiposity, body weight, body mass index, percent of body fat, visceral fat area, and waist and hip circumference were measured. For the inflammation and hormone markers, leptin, adiponectin, insulin, tumor necrosis factor-α, and interleukin-6 were also analyzed. Results: Multivariate linear regression analyses suggested that dietary sodium intake was not associated with adiposity. However, dietary sodium showed a significant association with insulin level: Plasma insulin concentration increased with sodium intake independent of other dietary intake or percent of body fat (β = 0.296, adjusted r 2 = 0.276, p < 0.01). Other markers for inflammation and hormonal responses were not associated with dietary sodium intake. Conclusion: Findings suggested that dietary sodium intake may be a critical modifying factor in the level of plasma insulin. However, it showed a limited effect on obesity and other inflammation markers and hormone levels. These findings should be confirmed in larger, well-designed investigations.

The association between dietary sodium intake, adiposity and sugar-sweetened beverages in children and adults: a systematic review and meta-analysis

“…Fifty-nine cross-sectional studies reported on the association between sodium intake and a measure of adiposity (Table S3) (9-12, 35, 51-104) , 33 of these were included in meta-analyses (9-11, 53, 59, 60, 62, 63, 65-67, 69-71, 73, 75, 76, 79, 80, 83, 85, 88, 91, 93, 95, 97-104) . Reasons for exclusion from metaanalyses included; findings were only presented as correlation coefficients (n=16) (35, 54-56, 61, 68, 77, 78, 81, 82, 84, 86, 87, 90, 92, 96) or as standardised regression coefficients (n=4) (57,64,89,94) , the exposure variable was presented as sodium density (n=2) (12,72) or 24-hr urinary sodium excretion was reported as sodium concentration (mmol/L) (74) or on a logarithmic scale (52,58) . Of the studies included in meta-analyses, 14 were from Asia (62,63,66,69,70,73,75,76,83,85,91,97,100,101) , eight from USA (10,11,59,60,71,88,102,103) , five from South and Central America (53,65,79,80,93) , four from Europe (9,67,…”

“…One study reported a weak positive correlation between sodium intake and WC (unadjusted) (78) , three studies adjusted for a range of covariates and reported positive associations between sodium intake and waist circumference (10,11,74) and one study reported a positive association between sodium density and abdominal obesity (12) . Two studies, both of which adjusted for a range of covariates (57,58) , reported null findings and the final study reported mixed findings, with no relationship between sodium density and waist circumference, yet a positive association between sodium density and abdominal obesity (72) .…”

“…On the contrary three studies reported null findings (57,58,68) (2/3 adjusted for a range of covariates including energy intake).…”

“…Across the 6 studies (52,57,58,74,89,94) which reported results as linear regression analysis, all but two of these studies (57,58) reported positive associations between sodium intake and BMI (Table S5). The final study which reported mean BMI across ntile of sodium density (i.e.…”

“…Across the thirteen studies (35,54,56,61,68,77,78,81,82,84,86,90,92) which reported results as a correlation coefficient, all but one (56) reported weak-to-moderate positive correlations between Na intake and BMI (range r 0•11-0•45) (online Supplementary Table S5). Across the six studies (52,57,58,74,89,94) which reported results as linear regression analysis, all but two of these studies (57,58) reported positive associations between Na intake and BMI (online Supplementary Table S5). The final study which reported mean BMI across ntile of Na density (i.e.…”