Healthy lifestyle behaviors are well established to be associated with a lower risk of cardiometabolic diseases and mortality, both in general populations and individuals at high risk of diabetes. Evidence about their effect on the risk of microvascular complications of diabetes is scarcer.

Using two large prospective cohorts, researchers have now demonstrated that adherence to healthy practices both before and after a diabetes diagnosis is significantly associated with a lower risk of microvascular complications. Qi Sun, MD, ScD, of the Channing Division of Network Medicine in the Department of Medicine at Brigham and Women’s Hospital, Giorgio Giatsidis, MD, PhD, formerly of the Brigham’s Department of Surgery, Gang Liu, PhD, of the Huazhong University of Science and Technology, and colleagues report the findings in JAMA Network Open.

Study Participants

The data sources for the study were the Nurses’ Health Study, initiated in 1976, which enrolled 121,700 U.S. female registered nurses ages 30 to 55, and the Health Professionals Follow-Up Study, initiated in 1986, which enrolled 51,529 U.S. male health professionals ages 40 to 75.

Participants in both cohorts complete questionnaires on diet, lifestyle, medical history, and newly diagnosed diseases every two to four years.

The current analysis included 7,077 participants (4,982 women and 2,095 men; mean age 61, 94% white) who had new-onset type 2 diabetes diagnosed during follow-up and completed supplemental questionnaires about diabetes treatments and complications.

Lifestyle Factors

Five modifiable lifestyle-related factors were assessed. Participants received one point for each of the following:

• Diet score in the upper 40^th percentile of the study population on the 2010 Alternate Healthy Eating Index
• Body mass index ≥18.5 and <25 kg/m²
• Current nonsmoker
• Alcohol consumption of 5–15 g/day for women and 5–30 g/day for men
• 150 minutes/week of moderate-to-vigorous physical activity that required expenditure of ≥3 metabolic equivalents per hour

Thus, the total score ranged from 0 to 5 with 5 representing the healthiest lifestyle.

Results

2,878 new-onset diabetic microvascular complications were documented during follow-up. In multivariable analyses, a lifestyle score of 4 or 5 before a diagnosis of diabetes was associated with a significantly lower risk of complications compared with a score of 0:

• Any microvascular complication—RR, 0.73 (P for trend, 0.006)
• Diabetic neuropathy—RR, 0.71 (P for trend, 0.01)
• Diabetic retinopathy—RR, 0.76 (P for trend, 0.09)
• Diabetic nephropathy—RR, 0.42 (P for trend, 0.01)
• Diabetic foot disorders (amputation of toe, foot, or leg)—RR, 0.60 (P for trend, 0.049)

The results were similar for a healthy lifestyle after diabetes diagnosis:

• Any microvascular complication—RR, 0.68 (P for trend <0.001)
• Diabetic neuropathy—RR, 0.67 (P for trend <0.001)
• Diabetic retinopathy—RR, 0.65 (P for trend, 0.09)
• Diabetic nephropathy—RR, 0.57 (P for trend, 0.20)
• Diabetic foot disorders—RR, 0.62 (P for trend, 0.03)

Greater improvements in lifestyle factors from before to after diabetes diagnosis were significantly associated with lower risk of:

• Any microvascular complication—RR, 0.94 (P=0.01) for each increment of low-risk factors
• Diabetic neuropathy—RR, 0.91 (P=0.001) for each increment of low-risk factors

Conclusions

Along with previous research, these results suggest adherence to a healthy lifestyle could help people with type 2 diabetes prevent microvascular complications. They support the American Diabetes Association guidelines that recommend lifestyle improvements for individuals with diabetes.