Effect of early diagnosis and lifestyle modification on functional activities in community-dwelling elderly adults with glucose intolerance: 5-year longitudinal study.

Abstract

To the Editor: Older people with diabetes mellitus frequently have functional impariment,1-4 but there are few reports of the protective effects of longitudinal interventions on functional decline in older people newly diagnosed according to an oral glucose tolerance test (OGTT).5 The association between glucose intolerance and decline in instrumental activities of daily living (IADL) was examined to verify the hypothesis that annual education on lifestyle modification can help prevent IADL decline in people with glucose intolerance in a 5-year longitudinal study. Community-dwelling people aged 60 and older were screened using an OGTT (World Health Organization criteria) for the first time in 2006 in Tosa, Japan5 (N = 378; 212 with normal glucose tolerance (NGT), 127 with impaired glucose tolerance (IGT), 39 with diabetes mellitus (DM)). The prevalence at baseline of disability in IADLs (≤4 of five of the IADL items in the Tokyo Metropolitan Institute of Gerontology index),6, 7 was 9.0% for NGT, 15.7% for IGT, and 30.8% for DM (P < .001, chi-square test). DM (odds ratio (OR) = 4.42, 95% confidence interval (CI) = 1.62–12.08, P = .004) and IGT (OR = 2.23, 95% CI = 1.03–4.82, P = .04) were associated with IADL disability as assessed using multiple logistic regression after adjusting for dependent basic activities of living (ADL) (OR = 5.12, 95% CI = 1.99–13.18, P < .001),8 age, sex, depression,9 body mass index (BMI), and falling (Figure 1A). Of the 289 participants who were independent in IADLs (score of 5) at baseline, who could be followed up during the 5-year study, the incidence of IADL disability was 15.6% for NGT, 11.8% for IGT, and 23.1% for DM groups. DM (OR = 2.70, 95% CI = 0.87–8.39 vs NGT, P = .09) was mildly associated with decline in IADL ability, but IGT was not, as indicated by multiple logistic regression after adjusting for dependence in ADLs (OR = 3.01, 95% CI = 1.03–8.82, P = .04), depression (OR = 2.77, 95% CI = 0.94–8.15, P = .06), age, sex, falling, and BMI (Figure 1B). All subjects were invited to participate in the five annual glucose intolerance and geriatric functional analyses and education about lifestyle modification during the 5-year study period.5, 10 To analyze the preventive effect of follow-up participation of participants with NGT, IGT and DM on IADL decline, all subjects were assigned to one of two groups: more participation (≥4) or less participation (≤3). In each NGT, IGT, and DM group, the odds of more participation compared with less participation were calculated for IADL decline during the 5 years (Figure 1C). In NGT and IGT, more participation had a protective effect on IADL decline (group 2 vs 1: OR = 0.28, 95% CI = 0.09–0.86, P = .03; group 4 vs 3: OR = 0.093, 95% CI = 0.011–0.780) vs group 3, P = .03) after adjustment for age, sex, ADL dependence, and depression. With DM, there was no significant difference between the groups with less and more participation. At baseline, no subject was taking anti-DM medication, but during the following 5-year study period, 11 in the DM or IGT group started taking anti-DM medication. The results showed no difference in the incidence of IADL disability between those taking and not taking medication. In the analysis of subjects not taking anti-DM medication during the study, the significant protective effect on IADL decline in the group with more participation was preserved in IGT group. Despite the strong association between DM and IGT and IADL disability at baseline, IADL decline during the 5-year study period was mildly associated with DM but not with IGT. Lifestyle modifications were associated with less IADL decline in people with IGT in annual follow-up visits. Improvement in DM indicators was made using nonpharmaceutical intervention through lifestyle modification in the community.5 Diligent dieting and exercise in the groups with more participation might have preserved IADLs during the 5-year period. In conclusion, early diagnosis and annual follow-up using nonpharmaceutical interventions for lifestyle modification in elderly adults with glucose intolerance may be effective in the longitudinal preservation of functional abilities. We thank all staff members and participants in Tosa town for their assistance and collaboration in the study. The Ethics Committees of Kyoto University and the Research Institute for Humanity and Nature approved this study. Conflict of Interest: None. Author Contributions: Okumiya, Matsubayashi, Otsuka: study design. Okumiya, Sakamoto, Wada, Imai, Matsubayashi: data analysis, writing manuscript. Okumiya, Sakamoto, Fujisawa, Wada, Chen, Imai, Ishimoto, Kimura, Fukutomi, Kato, Tanaka, Hirosaki, Kimura, Nakatsuka, Ishine, Yamamoto, Okumiya, Matsubayashi: participation in baseline or follow-up study. Okumiya, Sakamoto, Fujisawa, Wada, Chen, Imai, Ishimoto, Kasahara, Fukutomi, Sasiwongsaroj, Kato, Tanaka, Hirosaki, Nose, Nakatsuka, Yamamoto, Matsubayashi: discussion. Sponsor's Role: None.