Timing and duration of obesity in relation to diabetes: findings from an ethnically diverse, nationally representative sample

Abstract

Objective: The influence on diabetes of the timing and duration of obesity across the high-risk period of adolescence to young adulthood has not been investigated in a population-based, ethnically diverse sample.

Research design and methods: A cohort of 10,481 individuals aged 12-21 years enrolled in the U.S. National Longitudinal Study of Adolescent Health (1996) was followed over two visits during young adulthood (18-27 years, 2001-2002; 24-33 years, 2007-2009). Separate logistic regression models were used to examine the associations of diabetes (A1C ≥6.5% or diagnosis by a health care provider) in young adulthood with 1) obesity timing (never obese, onset <16 years, onset 16 to <18 years, onset ≥18 years) and 2) obesity duration over time (never obese, incident obesity, fluctuating obesity, and persistent obesity), testing differences by sex and race/ethnicity.

Results: Among 24- to 33-year-old participants, 4.4% had diabetes (approximately half were undiagnosed), with a higher prevalence in blacks and Hispanics than whites. In multivariable analyses, women who became obese before age 16 were more likely to have diabetes than women who became obese at or after age 18 (odds ratio 2.77 [95% CI 1.39-5.52]), even after accounting for current BMI, waist circumference, and age at menarche. Persistent (vs. adult onset) obesity was associated with increased likelihood of diabetes in men (2.27 [1.41-3.64]) and women (2.08 [1.34-3.24]).

Conclusions: Diabetes risk is particularly high in individuals who were obese as adolescents relative to those with adult-onset obesity, thus highlighting the need for diabetes prevention efforts to address pediatric obesity.

Figure 1

Prevalence of diabetes in adulthood by obesity timing (A), obesity duration from adolescence to adulthood (B), and diagnosed and undiagnosed diabetes stratified by race/ethnicity (C), from wave IV (2007–009) of the Add Health study. A: Timing of obesity was determined using the individual’s age at the wave of initial obesity classification and categorized as follows: 1) never obese; 2) adolescent obesity (onset before 16 years of age); 3) adolescent obesity (onset at or after age 16 to before age 18); and 4) adult obesity (onset at or after the age of 18 years). B: Obesity duration from adolescence to adulthood was based on obesity status at waves II, III, and IV and categorized as follows: 1) never obese; 2) incident obesity (nonobese at baseline and became and remained obese through last examination); 3) fluctuating obesity (any shift in classification from obese to nonobese); and 4) persistent obesity (obese at all waves). Prevalence of diabetes was based on total diabetes, which includes (C) both diagnosed diabetes (self-reported health care provider diagnosis of diabetes) and undiagnosed diabetes (A1C ≥6.5% with no reported diabetes diagnosis) unless otherwise noted.