Association of serum creatinine levels and risk of type 2 diabetes mellitus in Korea: a case control study

BACKGROUND: Reduced skeletal muscle has been suggested as a potential risk factor for type 2 diabetes mellitus (T2DM). Serum creatinine is the primary metabolite of creatine in skeletal muscle. Therefore, low serum creatinine levels may be associated with an increased risk of T2DM. We aimed to evaluate the association between serum creatinine levels and the risk of T2DM in Korea. METHODS: We analyzed a total of 264,832 nondiabetic adults older than 40 years of age who had undergone a national health examination at least once from 2009 to 2015 in the Korean National Health Insurance Service Cohort. Hazard ratios for T2DM were calculated. RESULTS: In men, serum creatinine levels and the risk for T2DM showed an inverse J-shaped association. This association was confirmed after adjustment for age, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), and fasting plasma glucose. In women, there was a trend that serum creatinine levels were inversely associated with the risk of T2DM among those with serum creatinine below 1.1 mg/dl. However, serum creatinine levels were not significantly associated with the risk of T2DM after adjustment for age, BMI, SBP, DBP, and fasting plasma glucose. CONCLUSIONS: Reduced levels of serum creatinine were significantly associated with an increased risk of T2DM in men with creatinine below 1.20 mg/dl. There was a trend that decreased levels of serum creatinine were associated with an increased risk of T2DM among women with serum creatinine below 1.1 mg/dl, although this result was not statistically significant.