Magnitude of the association of ideal CV health with lower diabetes risk varies by glycemic status
Ideal cardiovascular health, glycaemic status and incident type 2 diabetes mellitus: the REasons for Geographic and Racial Differences in Stroke (REGARDS) study
Introduction and methods
Life’s Simple 7, created by the American Heart Association, consists of 7 health factors or behaviors associated with a lower incidence of CVD, all-cause mortality and diabetes: total cholesterol <5.18 mmol/l, blood pressure <120/<80 mmHg. fasting plasma glucose <5.6 mmol/l, healthy dietary pattern, no (prior) smoking, 150 min/week of moderate intensity or 75 min/week of vigorous intensity physical activity and BMI <25 kg/m2 [1-5]. It is not clear whether the association of ideal CV health (CVH) with diabetes risk is also true for individuals with higher levels of diabetes risk (impaired fasting glucose [IGF]: 5.6-6.9 mmol/L) compared to those with lower risk (normal fasting glucose [NFG]: <5.6 mmol/L) [5,6].
The REasons for Geographic and Racial Differences in Stroke (REGARDS) study is a prospective national cohort of community-dwelling African-American and white adults ≥45 years . Baseline characteristics were collected from 2003-2007 using validated questionnaires and measures were collected during an in-home examination by trained staff. Number of ideal CVH metrics was summed across the 6 metrics (7 metrics minus fasting plasma glucose, as diabetes was the outcome of interest) and categorized as poor (0–1, ideal metrics), intermediate (2–3 ideal metrics) and ideal (4+ ideal metrics) CVH. The primary outcome of incident diabetes was assessed in 7758 participants. Median follow-up was 9.5 years (IQR: 8.6–9.9 years).
- RRs for incident diabetes with 2–3 ideal CVH components or ≥4 ideal CVH components compared with 0–1 ideal CVH components were 0.70 (95% CI 0.62-0.79) and 0.29 (95% CI 0.20-0.41), respectively.
- Having ≥4 ideal CVH metrics vs 0-1 ideal CV metrics was associated with a lower risk of incident diabetes in subjects with NFG than in those with IFG (RR 0.20, 95% CI:0.10-0.37 vs RR 0.87, 95%CI:0.58-1.30, P for interaction by glycemic status<0.0001). Looking at the individual components, there were significant differences for BMI, blood pressure, smoking and dietary intake by glycemic status.
- Having 2–3 and ≥4 ideal CVH components vs 0–1 ideal CVH components was associated with a lower risk of incident diabetes in white participants (39% and 73%) compared to African-Americans (14% and 66%)(P for interaction=0.03).
A strong inverse association between CVH and incidence of diabetes was observed for those with NFG and no association was seen for those with IFG. Tailored management that takes in account the differences by race and glycemic status is needed to prevent the development of diabetes.