Outcome of lifestyle intervention in relation to duration of pre-diabetes: the Pathobiology and Reversibility of Prediabetes in a Biracial Cohort (PROP-ABC) study

Abstract

Introduction: In studies that enrolled people with prevalent pre-diabetes of unknown duration, lifestyle intervention (LI) delayed progression to type 2 diabetes (T2D) but did not reverse pre-diabetes in most participants. Here, we assessed the effects of LI among individuals with pre-diabetes of known duration to determine whether outcomes are related to duration of pre-diabetes.

Research design and methods: The Pathobiology and Reversibility of Prediabetes in a Biracial Cohort study initiated LI in subjects with incident pre-diabetes during follow-up of initially normoglycemic African Americans and European Americans with parental T2D. Participants were stratified into those initiating LI after <3, 3-5, or >5 years of pre-diabetes diagnosis. Assessments included anthropometry, body fat, fasting and 2-hour plasma glucose (FPG, 2hPG), and insulin sensitivity and secretion. The outcomes were normal glucose regulation (NGR; ie, normal FPG and 2hPG), persistent pre-diabetes, or T2D. Participants who maintained normal FPG and normal 2hPG levels during follow-up served as the control. The control subjects did not receive lifestyle or other intervention to alter the course of glycemia or body weight.

Results: Of 223 participants (age 53.3±9.28 years, body mass index 30.6±6.70 kg/m²), 72 (control) maintained normoglycemia during follow-up and 138 subjects with incident pre-diabetes initiated LI after 4.08±2.02 years (range 3 months-8.3 years) of diagnosis. Compared with control, LI participants showed decrease in glucose, weight, and body fat; 42.8% reverted to NGR, 50% had persistent pre-diabetes, and 7.2% developed T2D after 5 years. These outcomes were similar across race and pre-diabetes duration strata, but greater glycemic decrease occurred when LI was initiated within 5 years of pre-diabetes diagnosis.

Conclusions: Ninety-three per cent of adults with parental T2D who initiated LI within 3 months to 8.3 years of developing pre-diabetes did not progress to T2D; nearly half reverted to NGR.Trial registration number NCT02027571.

Keywords: diet; ethnic groups; exercise; prediabetic state.

Figure 1

Enrollment data showing flow of participants from POP-ABC to PROP-ABC study. AA, African American; EA, European American; POP-ABC, Pathobiology of Prediabetes in a Biracial Cohort; PROP-ABC, Pathobiology and Reversibility of Prediabetes in a Biracial Cohort.

Figure 2

Changes in (A) body weight and (B) waist circumference in participants receiving lifestyle intervention (closed circles) versus control subjects (open circles); (C) weight change in African Americans (striped bars) and European Americans (open bars) and (D) in relation to physical activity during 5 years of lifestyle intervention. Repeated measures ANOVA p=0.037 for weight change, p=0.03 for change in waist circumference; weight change did not differ significantly by sex or race/ethnicity. ANOVA, analysis of variance.

Figure 3

(A) Serial changes in FPG in participants receiving lifestyle intervention (closed circles) versus control subjects (open circles). (B) Changes in FPG among African American (striped bars) and European American (open bars) lifestyle participants. Proportion of (C) all lifestyle participants and (D) African Americans (striped bars) and European Americans (open bars) with NGR, pre-diabetes, and diabetes after lifestyle intervention. Repeated measures ANOVA p=0.0008 for FPG change in lifestyle intervention participants versus control subjects. ANOVA, analysis of variance; FPG, fasting plasma glucose; NGR, normal glucose regulation.