Undiagnosed diabetes mellitus among residents in Taiwanese long-term care facilities: A comparison of fasting glucose, postprandial plasma glucose, and hemoglobin A1c

Background The prevalence of diabetes mellitus (DM) is escalating with an aging population, and the chances of diabetic older patients admitted to long-term care facilities (LTCFs) are increased because of DM-related complications. However, undiagnosed DM among LTCF residents is a recognized hidden problem in this setting and may result in adverse outcomes. Methods In May 2011, 10 private LTCFs in northern Taipei participated in this study. Trained research nurses reviewed the medical records and performed physical examinations and blood sampling for all participants. Diabetes mellitus was diagnosed, based on the levels of fasting glucose, 2-hour postprandial plasma glucose, and hemoglobin A1c (HbA1c). Patients were categorized as having DM if they met the diagnostic cut-offs of the aforementioned criteria. Results One hundred and ninety-nine residents (mean age, 79.6 ± 10.5 years; 52.3% males) participated in this study. They were all moderately/severely disabled (Karnofsky Performance Scale mean score was 50 ± 13). Forty-six (23.1%) residents were diabetic, based on their medical records, or were current users of antidiabetic agents. The prevalence was 29.6% after testing with a mean HbA1c level of 6.9% ± 0.9%. The overall undiagnosed DM rate was 4%, 3.5%, and 4.5%, based on fasting glucose, 2-hour postprandial plasma glucose, and HbA1c criteria, respectively. Diabetic patients had significantly higher serum levels of prealbumin, compared to nondiabetic patients (220.8 ± 45.9 vs. 201.1 ± 62.2 mg/L; p = 0.03), but there were no differences in the levels of hemoglobin, serum albumin, or total cholesterol. Diabetic patients had a significantly higher serum triglyceride level, compared to the nondiabetic patients (1.6 ± 0.7 vs. 1.1 ± 0.5 mmol/L; p < 0.01) and a lower high-density lipoprotein level (1.0 ± 0.3 vs. 1.2 ± 0.3 mmol/L; p < 0.01). Among 43 pharmacologically treated diabetic patients, 65.1% (28/43) of patients were using oral antidiabetic agents and 41.9% (18/43) of patients had been prescribed insulin, whereas 32.6% of the patients were managed by combination therapy. Conclusion The prevalence of DM among LTCF residents in Taipei was 29.6%, and the undiagnosed rate was no more than 5%, based on fasting glucose, 2-hour postprandial plasma glucose, or HbA1c. Further study is needed for the optimal treatment strategy of DM in LTCFs.