Adult-Onset Autoimmune Diabetes is Largely due to Modifiable Risk Factors: Results from the Norwegian HUNT Study

Bahareh Rasouli Tomas Andersson

doi:10.4172/2155-6156.1000306

Abstract

Introduction: Adult-onset autoimmune diabetes is prevalent, yet there are limited data on risk factors. Aim: Our aim was to examine how combinations of modifiable lifestyle factors are associated with risk of adultonset autoimmune diabetes and to estimate the Population Attributable Risk (PAR) related to such factors. Methods: We used incidence data from Nord-Trondelag Health Survey Study (HUNT), a large population-based study where adults aged ≥ 20 years old were investigated in three consecutive surveys during 1984-2008 (n=49,712; eligible for this study).Among self-reported diabetes patients, presence of Glutamic Acid Decarboxylase Antibodies (GADA) and age at onset ≥ 35 years old were used to identify incident cases of adult-onset autoimmune diabetes (n=164). Hazard Ratios (HR) of autoimmune diabetes by lifestyle factors were estimated by Cox regression and PAR were calculated for single items and combination of lifestyle factors. Results: A reduced risk of adult-onset autoimmune diabetes was conferred by BMI<25, physical activity, regular alcohol consumption and psychosocial well-being. Positivity for all four healthy lifestyle factors gave a HR of 0.10 (95% CI=0.02-0.40) compared with no positivity. Estimation of PAR indicated that 69% (CI=45-79%) of all cases of adult-onset autoimmune diabetes could be prevented through these factors with BMI< 25 as the most important contributor (PAR for BMI ≥ 25= 34%, CI=20-48%). Conclusions: Provided that these associations are causal, then the majority of adult-onset autoimmune diabetes cases are preventable by modification of common lifestyle factors primarily by maintaining a BMI in the non-overweight range.

Highlights

Adult-onset autoimmune diabetes is prevalent, yet there are limited data on risk factors
Adult-onset autoimmune diabetes may be the second most common form of diabetes, accounting for 2-12% of all cases of diabetes [8]. It is often sub-grouped into classical type1 diabetes and latent autoimmune diabetes in adults (LADA), the most frequent form of autoimmune diabetes in adults, which compared to classical type 1 diabetes, progresses more slowly and requires insulin treatment at a later stage [9,10]
The relative lack of studies on risk factors may be attributable to the fact that in most observational studies, cases of adult-onset autoimmune diabetes cannot be separated from cases of type 2 diabetes due to lack of information on indicators of autoimmunity such as antibodies against glutamic acid decarboxylase– Glutamic Acid Decarboxylase Antibodies (GADA)

Summary

Introduction

Adult-onset autoimmune diabetes is prevalent, yet there are limited data on risk factors. It is well-known that the risk of type 2 diabetes can be reduced by lifestyle modification including; normal weight [1], regular physical activity [2], moderate alcohol consumption [3], healthy diet [4], and by refraining from smoking [5]. There are few studies on risk factors for autoimmune diabetes in adults [11,12,13,14,15] and as far as we know, no investigations on the preventive potential of a healthy lifestyle in this form of diabetes. The relative lack of studies on risk factors may be attributable to the fact that in most observational studies, cases of adult-onset autoimmune diabetes cannot be separated from cases of type 2 diabetes due to lack of information on indicators of autoimmunity such as antibodies against glutamic acid decarboxylase– GADA

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