[Background characteristics and clinical features of elderly patients with hyperglycemic hyperosmolar syndrome].

Aim: Few reports have described the characteristics of hyperglycemic hyperosmolar syndrome (HHS) in the elderly. We investigated the background characteristics and clinical features of 14 elderly patients with HHS.

Methods: HHS was diagnosed based on a blood glucose level of >600 mg/dL and an effective plasma osmolality [2 (Na) + glu/18] of >320 mOsm/kg. For 14 cases of HHS, we investigated the medical and social backgrounds of the patients, their clinical findings, and the outcomes.

Results: The mean patient age was 83 years, and the mean body mass index was 17.8 kg/m. Half had a history of either cerebral infarction or hip fracture. The mean duration of diabetes was 14 years, but 4 diabetes cases were newly diagnosed. There was a high prevalence of acute infection (79%) in HHS patients, especially urinary tract infection and pneumonia, with a seasonal peak in winter. Patients who had been treated with steroids, tube feeding, or both numbered 1, 2, and 1, respectively. Most HHS patients had a history of dementia. More than half of such patients were living alone or only with their spouse, and their activities of daily living showed marked deterioration. The mean blood glucose level, HbA1c, effective serum osmolality, and pH were 881 mg/dL, 10.3%, 353 mOsm/kg, and 7.39, respectively. One patient died during hospitalization, and 9 were discharged to nursing homes or other hospitals. The mean length of hospitalization was 55 days. In most cases, the insulin secretion capacity was preserved, and 9 patients were treatable with oral hypoglycemic agents alone.

Conclusions: Many cases of HHS in the elderly are associated with infection, a shortage of social support, cognitive impairment, or ADL decline. Although the survival rate in our series was high, the functional prognosis was impaired.