The relationship between resting heart rate and new-onset microalbuminuria in people with type 2 diabetes: An 8-year follow-up study.

AIMS: Microalbuminuria is an indicator of adverse cardiovascular events and chronic kidney disease. Studies have described an elevated resting heart rate as a risk factor for microalbuminuria in people with cardiovascular disease, but none have clarified its role in microalbuminuria development in people with type 2 diabetes. Therefore, this study investigated the relationship between resting heart rate and new-onset microalbuminuria in type 2 diabetes. METHODS: A total of 788 people from a glycaemic control trial in Taiwan were enrolled. Microalbuminuria was defined as a fasting urine albumin-to-creatinine ratio ≥30 mg/g in two consecutive urine tests. Resting heart rate and other covariates were measured at baseline. The quartile of resting heart rates, categorized as <70, 70-74, 75-80 and >80 beats/min, was used for analysis. Cox proportional hazard models were used to evaluate the association between resting heart rate and risk of microalbuminuria. RESULTS: During the follow-up period, 244 people (31%) developed microalbuminuria. Those who developed microalbuminuria had a longer diabetes duration (median = 3.0 vs. 2.0 years, p < 0.001), higher rate of hypertension (77% vs. 66%, p = 0.003), higher rate of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker treatment (50% vs. 38%, p = 0.001) and higher baseline HbA1c level (70 vs. 64 mmol/mol, 8.6 vs. 8.0%, p < 0.001). After adjusting for demographics, metabolic profiles and inflammatory markers, developing microalbuminuria was significantly associated with baseline resting heart rate of 70-74, 75-80 and >80 beats/min (with hazard ratios [95% CI] of 2.05 [1.32, 3.18], 2.10 [1.32, 3.32] and 1.62 [1.01, 2.59], respectively) compared to resting heart rates <70 beats/min. An average increased risk of microalbuminuria for increment of 10 beats/min was about 24% among those with hypertension (with hazard ratios of 1.24 [1.05, 1.47] in the multivariable Cox model). CONCLUSIONS: This prospective cohort study showed that resting heart rate may be an associative risk factor for developing microalbuminuria in type 2 diabetes.