Abstract
BACKGROUND: The prevalence of kidney stone disease is rising along with increasing rates of obesity, type 2 diabetes mellitus (T2DM), and metabolic syndrome. OBJECTIVE: To investigate the associations among the presence and severity of T2DM, glycemic control, and insulin resistance with kidney stone disease. DESIGN, SETTING, AND PARTICIPANTS: We performed a cross-sectional analysis of all adult participants in the 2007-2010 National Health and Nutrition Examination Survey (NHANES). A history of kidney stone disease was obtained by self-report. T2DM was defined by self-reported history, T2DM-related medication usage, and reported diabetic comorbidity. Insulin resistance was estimated using fasting plasma insulin (FPI) levels and the homeostasis model assessment of insulin resistance (HOMA-IR) definition. We classified glycemic control using glycosylated hemoglobin A1c (HbA1c) and fasting plasma-glucose levels (FPG). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Odds ratios (OR) for having kidney stone disease were calculated for each individual measure of T2DM severity. Logistic regression models were fitted adjusting for age, sex, race/ethnicity, smoking history, and the Quételet index (body mass index), as well as laboratory values and components of metabolic syndrome. RESULTS AND LIMITATIONS: Correlates of kidney stone disease included a self-reported history of T2DM (OR: 2.44; 95% confidence interval [CI], 1.84-3.25) and history of insulin use (OR: 3.31; 95% CI, 2.02-5.45). Persons with FPG levels 100-126 mg/dl and >126 mg/dl had increased odds of having kidney stone disease (OR 1.28; 95% CI, 0.95-1.72; and OR 2.29; 95% CI, 1.68-3.12, respectively). Corresponding results for persons with HbA1c 5.7-6.4% and ≥ 6.5% were OR 1.68 (95% CI, 1.17-2.42) and OR 2.82 (95% CI, 1.98-4.02), respectively. When adjusting for patient factors, a history of T2DM, the use of insulin, FPI, and HbA1c remained significantly associated with kidney stone disease. The cross-sectional design limits causal inference. CONCLUSIONS: Among persons with T2DM, more-severe disease is associated with a heightened risk of kidney stones.