Effect of a continuous diabetes lifestyle intervention program on male workers in Korea

Abstract

Aims

This study was conducted to compare the effects of two years of lifestyle intervention to no intervention or one year of intervention on diabetes risk factors in male workers with impaired fasting glucose (IFG) or diabetes.

Methods

We conducted a randomized lifestyle intervention trial designed to alter personal lifestyles among 123 industrial male workers (CG; control group, n = 75; OIG; one-year intervention group, n = 23; TIG; two-year intervention group, n = 25). The intervention consisted of two parts, the main program (face-to-face counseling five times/12 weeks) and a follow-up program (e-mail counseling ten times/30 weeks). Assessments included biochemical characteristics, anthropometry and nutrient intake at baseline and after two years.

Results

After two years, systolic blood pressure, HOMA-IR, HDL cholesterol and total energy intake (p < 0.05) were reduced in the OIG group, while weight, body mass index, waist circumference, blood pressure, fasting plasma glucose (FPG), HbA1c and nutrient intake (total energy, carbohydrate, protein and sodium) were significantly decreased (p < 0.05, respectively) in the TIG group. When compared to the CG, subjects in OIG and TIG showed significant improvements in the level of FPG and HbA1c (p < 0.05).

Conclusions

Continuous lifestyle intervention for two years is more effective at improving diabetes risk factors than OIG.

Introduction

Subjects with diabetes and pre-diabetes (including impaired fasting glucose (IFG) and impaired glucose tolerance (IGT)) face a greater risk for the development of cardiovascular disease (CVD), particularly coronary heart disease, peripheral vascular disease and stroke [1], [2], [3], [4], [5]. Previous studies have investigated the feasibility and efficacy of intervention for the prevention and management of diabetes. Additionally, it has recently been demonstrated that multicomponent lifestyle intervention can prevent or at least postpone type 2 diabetes [6], [7], [8], [9], [10], [11]. Moreover, lifestyle interventions that focus on body weight control, physical activity and dietary change have been shown to be much more effective at reducing the incidence of diabetes than pharmacological intervention (metformin) [10].

In the China Da Qing Diabetes Prevention Study (CDQDPS), subjects with IGT who underwent long-term diet and/or were subject to exercise interventions showed a significant decrease in the incidence of diabetes over a 6-year period [12]. Additionally, a longitudinal follow-up of CDQDPS participants over 20 years (up to 14 years after the active intervention) revealed that combined intervention (diet + exercise) effectively prevented or delayed diabetes [13]. Similarly, a Finnish Diabetes Prevention Study (DPS) [14] revealed significantly greater improvements in clinical and metabolic characteristics and nutrient intake in the intervention group after three years when compared with the control group. The results of an extended follow-up of the DPS revealed that the effect of lifestyle intervention on diabetes risk remained after active lifestyle counseling was stopped [15]. Similar study was performed in the U.S. for over a decade (Diabetes Prevention Program and the following Diabetes Prevention Program Outcomes Study) and the results were quite similar to that of the DPS. After 10 years (treatment period: about 3 years, extended follow-up period: about 7 years), a reduction in diabetes incidence by either lifestyle (34%) or metformin (18%) therapy persisted for at least 10 years [16]. The results hold strong, however, only with an extended length of intervention. Short-term intervention studies have been found to have limited effects. For example, Chan et al. [17] reported that waist circumference and diastolic blood pressure improved, but that hemoglobin A1c (HbA1c) and HDL levels worsened at the end of 6 months. Moreover, Jacobs-van der Bruggen et al. [18] suggested that interventions be continued (with at least two counseling sessions) during the second year to sustain the potential long-term health and economic consequences of lifestyle interventions. These results indicate that sustainability of lifestyle intervention is required to achieve the desired long-term effects of lifestyle intervention.

The present study was conducted to determine if a continuous lifestyle intervention program reduced the number of diabetes-related factors and improved nutrient intake among male office workers with IFG and diabetes. The lifestyle intervention effect was analyzed by a comparison among three intervention programs (no intervention, one-year and two-year intervention).