Weight Loss Over Time May Reduce Risk for Diabetes Onset

There may be an association between weight changes from young adulthood to midlife over the course of 10 years and the development of incident diabetes, according to a study published in Diabetes Care.

Researchers conducted a retrospective study on data collected from the National Health and Nutrition Examination Survey (NHANES) to determine whether there was a relationship between incident diabetes and weight changes that occurred between young adulthood and midlife.  This study identified 21,554 individuals and placed them in one of four groups: 

• Stable non-obese (n=16,454): body mass index (BMI)_{age 25} <30 and BMI_{10 years prior} <30
• Losing (n=227): BMI_{age 25} ≥30 and BMI_{10 years prior} <30
• Gaining (n=3719): BMI_{age 25} <30 and BMI_{10 years prior} ≥30
• Stable obese (n=1154): BMI_{age 25} ≥30 and BMI_{10 years prior} ≥30

The purpose of the study was to determine whether individuals were at reduced risk for developing diabetes, over the course of 10 years, if they moved from an obese BMI to non-obese BMI compared with individuals who stayed as stable obese (“risk reduction”). In addition, the study investigated whether individuals considered stable obese were at a higher risk for developing incident diabetes over time compared with individuals considered to be stable non-obese (“residual risk”). 

Compared with stable obese individuals, individuals with the lowest risk for developing diabetes during the 10 years observed were individuals who maintained their weight at a stable non-obese BMI state (hazard ratio [HR] 0.22; 95% CI, 0.18-0.28).  Individuals in the “losing” and “gaining” groups were found to have a 0.33 (95% CI, 0.14-0.76) and 0.70 (95% CI, 0.57-0.87) times higher risk for developing incident diabetes, respectively, compared with individuals in the stable obese group. 

When the reference group was changed to individuals who maintained a non-obese BMI, there was no significant difference in the risk for developing incident diabetes in individuals who reported going from an obese BMI to a non-obese BMI and individuals who remained at a stable non-obese BMI (HR 1.47; 95% CI, 0.65-3.36).  Not surprisingly, individuals who started at a non-obese BMI and moved to an obese BMI and individuals who started and remained at an obese BMI during the 10 years observed had a 5.77- and 8.07-times higher rate of developing incident diabetes, respectively compared with individuals who remained at a normal BMI (95% CI, 4.63-7.18 and 95% CI, 6.28-10.38, respectively). 

Researchers estimated that if 25-year-old individuals were to lose weight and be at a non-obese BMI by midlife, 9.1% of incident diabetes could potentially be averted (95% CI, 5.3-12.8), while 64.2% of all incident diabetes could be theoretically averted if individuals between early adulthood and midlife maintained a weight within the normal range (95% CI, 59.4-68.3). 

It was concluded that individuals who remain or become obese between young adulthood and midlife are at a higher risk for developing incident diabetes compared with individuals who maintained a non-obese BMI during the same time period. 

Further, the risk reduction hypothesis was tested and  a significant reduction was found in the risk for diabetes onset in individuals who lost weight between young adulthood and midlife compared with individuals who remained obese. Therefore, clinicians should continue to encourage individuals who are obese to lose weight and individuals who are non-obese to maintain a non-obese state, as it this study shows that this reduces the risk for developing incident diabetes later in life.

Reference

Stokes A, Collins JM, Grant BF, et al. Obesity progression between young adulthood and midlife and incident diabetes: a retrospective cohort study of U.S. adults [published online March 5, 2017]. Diabetes Care. doi:10.2337/dc17-2336