Undiagnosed diabetes mellitus and metabolic control assessed by HbA1c among residents of nursing homes

Aims/hypothesis. Diabetes prevalence and diabetes care in residents of nursing homes is a neglected area of research although the growing number of elderly people with diabetes represents a growing challenge for health care in most countries. In this study, we used HbA(1c) measurement to estimate the percentage of residents with undiagnosed diabetes and the quality. of metabolic control of subjects with known diabetes in nursing homes. - Methods: All 41 nursing homes in the county of Heinsberg in Northrhine-Westfalia were asked to complete a structured questionnaire on the prevalence of known diabetes among all residents. In addition, all residents were offered measurement of glycated haemoglobin A1c (HbA(1c)) from a capillary blood sample. Undiagnosed diabetes was defined by a HbA(1c) level greater than 6.0%. - Results. 39 nursing homes participated in the study comprising 99.6% of all residents. Among the 1936 residents 507. (26.2%) were known to suffer from diabetes. Among the latter 37.0% were under insulin treatment. Blood samples for the determination of HbA(1c) were obtained from 979 subjects from 20 nursing homes. Among those 60 years old or above (n=843) the mean level of HbA(1c), in those with known diabetes was 7.3 +/- 1.5% and in those without 6.1 +/-0.9%. Only 16.7% of the subjects with known diabetes had a HbA(1c) greater than 8.5% indicating poor metabolic control. Among the residents previously not known to have diabetes 47.2% had a HbA(1c), equal to or greater than 6.1%, but among those only 8.5% had a HbA(1c) greater than 7.0%. Conclusions/interpretation: Although the prevalence of undiagnosed diabetes mellitus defined by HbA(1c) above the normal range in elderly nursing home residents is high, only few may require treatment. The quality of metabolic control among those with known diabetes mellitus is better than expected.