Sugary soda consumption and albuminuria: results from the National Health and Nutrition Examination Survey, 1999-2004

Abstract

Background: End-stage renal disease rates rose following widespread introduction of high fructose corn syrup in the American diet, supporting speculation that fructose harms the kidney. Sugar-sweetened soda is a primary source of fructose. We therefore hypothesized that sugary soda consumption was associated with albuminuria, a sensitive marker for kidney disease.

Methodology/principal findings: Design was a cross-sectional analysis. Data were drawn from the National Health and Nutrition Examination Survey (NHANES), 1999-2004. The setting was a representative United States population sample. Participants included adults 20 years and older with no history of diabetes mellitus (n = 12,601); after exclusions for missing outcome and covariate information (n = 3,243), the analysis dataset consisted of 9,358 subjects. Exposure was consumption of two or more sugary soft drinks, based on 24-hour dietary recall. The main outcome measure was Albuminuria, defined by albumin to creatinine ratio cutpoints of >17 mg/g (males) and >25 mg/g (females). Logistic regression adjusted for confounders (diet soda, age, race-ethnicity, gender, poverty). Interactions between age, race-ethnicity, gender, and overweight-obesity were explored. Further analysis adjusted for potential mediators: energy intake, basal metabolic rate, obesity, hypertension, lipids, serum uric acid, smoking, energy expenditure, and glycohemoglobin. Alternative soda intake definitions and cola consumption were employed.

Results: Weighted albuminuria prevalence was 11%, and 17% consumed 2+ sugary soft drinks/day. The confounder-adjusted odds ratio for sugary soda was 1.40 (95% confidence interval: 1.13, 1.74). Associations were modified by gender (p = 0.008) and overweight-obesity (p = 0.014). Among women, the OR was 1.86 (95% CI: 1.37, 2.53); the OR among males was not significant. In the group with body mass under 25 kg/m(2), OR = 2.15 (95% confidence interval: 1.42, 3.25). Adjustment for potential mediators and use of alternative definitions of albuminuria and soda consumption did not appreciably change results. Diet sodas were not associated with albuminuria.

Conclusions: Findings suggest that sugary soda consumption may be associated with kidney damage, although moderate consumption of 1 or fewer sodas does not appear to be harmful. Additional studies are needed to assess whether HFCS itself, overall excess intake of sugar, or unmeasured lifestyle and confounding factors are responsible.

Figure 1. Prevalence of albuminuria among NHANES 1999–2004 non-diabetics age 20 and over, unadjusted and adjusted for age, according to sugary soft drink consumption.

Figure 2. Adjusted Odds Ratios (aORs) comparing albuminuria among consumers of 2+ vs. 0–1 sugary soft drinks per day, stratified by body mass index (BMI) category.

Trend line shows a quadratic model fit to the aORs; vertical lines represent 95% Confidence Intervals. The aORs are adjusted for age, race, ethnicity, and poverty status, but not BMI. BMI is used only as a stratification variable. Figure excludes subjects with BMI<17.5 kg/m² (n = 61).

Figure 3. Adjusted Odds Ratios (aORs) comparing albuminuria among consumers of 2+ vs. 0–1 sugary soft drinks per day, according to interaction with body mass index (BMI).

Adjusted for diet soda consumption, age, race, ethnicity, poverty status, BMI, and BMI-squared.

Figure 4. U.S. trends in total sugar availability, High Fructose Corn Syrup (HFCS) availability, soft drink consumption, and incident diabetic end-stage renal disease (ESRD) over time.

Data on sweetener availability from USDA ; soft drink consumption from Nielsen and Popkin ; and incident diabetic ESRD from the United States Renal Data System .