Association Between Body Fat Mass and Kidney Stones in US Adults: Analysis of the National Health and Nutrition Examination Survey 2011-2018

Abstract

Background: The association between total and truncal body fat and kidney stone (KS) remains unclear.

Objective: To evaluate the association between total and truncal body fat and KS in the US adult population.

Design, setting, and participants: The National Health and Nutrition Examination Survey (NHANES) comprises a series of nationally representative cross-sectional surveys. Data from females and males aged 20-59 yr who participated in four 2-yr NHANES cycles between 2011 and 2018 were obtained.

Outcome measurements and statistical analysis: Multivariable-adjusted logistic regression models were used to investigate the association between dual-energy x-ray absorptiometry (DXA) scan-measured total and truncal body fat percentage and mass with KS.

Results and limitations: A total of 10 271 participants (50.3% females) were included. Weighted KS prevalence was 8.11% in femalesand 7.55% in males. In males, higher fat percentage was associated with higher odds of KS (per 5% total fat: odds ratio [OR] = 1.19, 95% confidence interval [CI] 1.08-1.32; per 5% truncal fat: OR = 1.22, 95% CI 1.10-1.35), particularly in those aged 40-59 yr (per 5% total fat: OR = 1.36, 95% CI 1.16-1.59; per 5% truncal fat: OR = 1.41, 95% CI 1.20-1.65, p-interaction < 0.05). In females, higher fat percentage was associated with higher odds of KS overall (per 5% total fat: OR = 1.23, 95% CI 1.10-1.37; per 5% truncal fat: OR = 1.20, 95% CI 1.08-1.33) and in both age groups (20-39 and 40-59 yr, p-interaction > 0.05). The observed associations were stronger in "other" ethnicities and non-Hispanic white. Similar patterns were observed for per 5 kg body fat mass.

Conclusions: Total and truncal fat parameters are associated with a higher prevalence of KS in adult females and males who are ≥40 yr old. Truncal fat mass may be at least equal or superior to total fat mass in assessing the association of body fat with KS. Further studies are warranted to elaborate on the pathophysiologic mechanism of this association to decrease the prevalence of KS.

Patient summary: Total and truncal body fat are associated with a higher prevalence of kidney stone (KS) in adult females and males aged ≥40 yr. Truncal fat mass may be similar or superior to total fat mass in assessing the association between body fat and KS.

Keywords: Dual-energy x-ray absorptiometry; Fat mass; Kidney stone; National Health and Nutrition Examination Survey; Obesity; Truncal obesity; Urolithiasis.