Burden of Albuminuria in US Adults and its Association with Obesity, Sex and Mortality: A Cross-sectional Analysis of NHANES 2003-2020

INTRODUCTION: Albuminuria is an early marker of kidney disease diagnosis, severity and progression. Obesity, a major public health concern in the United States, may contribute to the development of albuminuria; however, the obesity-albuminuria relationship remains incompletely defined. We hypothesized that albuminuria is more prevalent in obese individuals and is associated with poor survival. METHODS: . BMI was categorized into normal weight, overweight and obese. Albuminuria was defined as UACR ≥30 mg/g and categorized into three severity grades (mild, moderate, and severe). Logistic regression models were used to assess the association between obesity and albuminuria, and adjustment by sociodemographic and clinical factors was assessed. Survival across albuminuria severity grades was examined. RESULTS: Among individuals with albuminuria the prevalence of obesity was significantly higher than those without albuminuria (40.2% vs 32.9%; p<0.001). Individuals with albuminuria were relatively older and had higher prevalence of diabetes and hypertension as compared to the no albuminuria group. Obesity was significantly associated with higher odds of albuminuria (OR 1.36; 95% CI 1.23-1.50) when controlling for sociodemographic and clinical factors. We also observed higher odds of albuminuria in individuals who were males (OR 1.58, 95% CI 1.37-1.82), ages 18 to 44 years (OR 1.46, 95% CI 1.26-1.68), and ages 45 to 64 years (OR 1.79, 95% CI 1.49-2.14). The Individuals with albuminuria had poorer survival, with stark decline in a stepwise manner across albuminuria severity grades. CONCLUSION: Obesity is strongly associated with albuminuria in U.S. adults. Albuminuria is linked to survival disadvantage, underscoring the importance of screening among individuals with obesity and early initiation of nephro-protective therapies in individuals with albuminuria.