Drug use and increased HbA1c levels in non-diabetic very elderly persons: the Kungsholmen project.

OBJECTIVE: To examine the association between the use of drugs with potential hyperglycemic effects and increased HbA1c levels in a very elderly population. METHODS: This was a cross-sectional study of older subjects age 81 years and over from the second follow-up (1994-1996) of the Kungsholmen project, a population-based study of elderly in an urban area of Stockholm, Sweden. The study population consisted of 578 subjects, with a mean age of 86.7 years, without known diabetes mellitus. Glucose levels were assessed using HbA1c. Information on drug use was based on personal interviews. Diagnoses of diabetes mellitus, hypertension, and congestive heart failure were obtained from personal or relative interviews, assessment by the examining physician, and from the computerized inpatient register. Measures of other factors that may influence glucose homeostasis included body mass index, s-K(+), s-Ca(2+), thyroid stimulating hormone, and sedimentation rate. RESULTS: High HbA1c levels (>5.3%) indicating hyperglycemia were seen in 11% of the women and 12% of the men. Use of loop diuretics was significantly associated with high levels of HbA1c in both women and men, even after adjusting for hypertension and congestive heart failure. Eighteen percent of users of loop diuretics had high levels compared with 8% among non-users. CONCLUSION: Our results indicate that loop diuretics may have hyperglycemic effects in the very elderly. This finding can be of clinical importance as loop diuretics are among the most commonly taken drugs in this population.

Sodium and potassium disturbances in the elderly : prevalence and association with drug use.

OBJECTIVE: To study the incidence of sodium and potassium disturbances in a population of the very old elderly, with respect to medication with potential effects on electrolyte levels. DESIGN AND SETTING: Cross-sectional study of subjects aged >/=75 years, based on data from the Kungsholmen project, a population-based study of elderly in an urban area of Stockholm, Sweden. STUDY PARTICIPANTS: 1558 elderly individuals (1178 women and 380 men), mean age 81.4 years, providing information about drug use and serum electrolyte data. MAIN OUTCOME MEASURES: Data on drug use was based on personal interviews. Hyponatraemia was defined as a serum sodium concentration <136 mmol/L, hypernatraemia as a serum sodium concentration >146 mmol/L, hypokalaemia as a serum potassium concentration <3.5 mmol/L and hyperkalaemia as a serum potassium concentration >5.0 mmol/L. RESULTS: Hyponatraemia was found in 147 subjects (9.4% of the study population) and hypernatraemia in five individuals (0.3%). Hypokalaemia was found in 39 (2.5%) and hyperkalaemia in 43 (2.8%) of the subjects. The prevalence of hyponatraemia (p < 0.001), hypokalaemia (p < 0.05) and hyperkalaemia (p < 0.05) increased with age. Hyponatraemia was found more often in women than in men (p < 0.05). Hypernatraemia was more frequent in subjects who lived in institutions (p < 0.001). The occurrence of hyponatraemia was associated with the use of carbamazepine, laxatives (enema), diuretics and ACE-inhibitors; hypernatraemia was associated with osmotically active laxatives. Hypokalaemia was associated with thiazide-related and combination diuretics; and hyperkalaemia was associated with potassium-sparing diuretics, beta-blockers, cytostatic drugs and tricyclic antidepressants. CONCLUSIONS: The present study demonstrated the association between electrolyte level disturbances and several types of drugs in a population of the very old elderly. Our results underline the importance of monitoring serum electrolyte levels in the elderly, not only in relation to the use of diuretics, but also several other drugs.