Risk Factors for the Presence and Progression of Cardiovascular Autonomic Neuropathy in Type 2 Diabetes: ADDITION-Denmark

Abstract

OBJECTIVE To examine the course of cardiovascular autonomic neuropathy (CAN) and related cardiometabolic risk factors in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS CAN and cardiometabolic risk factors were assessed in the Danish arm of the Anglo-Danish-Dutch Study of Intensive Treatment in People With Screen-Detected Diabetes in Primary Care (ADDITION-Denmark) at 6-year (n = 777) and 13-year (n = 443) follow-up examinations. Cardiovascular autonomic reflex tests (CARTs)—that is, lying to standing, deep breathing, and the Valsalva maneuver—and 2-min resting heart rate variability (HRV) indices were obtained as the main measures of CAN. Risk factors related to CAN status, as determined by CARTs, were studied by using multivariate logistic regressions. The effects of risk factors on continuous CARTs and HRV indices, and their changes over time, were estimated in linear mixed models. RESULTS A progressive yet heterogeneous course of CAN occurred between the 6- and 13-year follow-ups. Higher HbA1c, weight, BMI, and triglycerides were associated with prevalent CAN. No significant effect of risk factors on CARTs was found when they were analyzed as continuous variables. CART indices decreased over time, and a trend of decreasing HRV indices was seen. Higher HbA1c and BMI were associated with lower HRV index values, but these differences diminished over time. CONCLUSIONS These data confirm that hyperglycemia, obesity, and hypertriglyceridemia are negatively related to indices of CAN, although these effects diminish over time. The observed heterogeneous course of CAN may challenge the present clinical approach of categorically classifying CARTs to diagnose CAN and the notion of CAN being irreversible.