Associations between serum electrolyte impairments and frailty status in older adults

Electrolyte imbalances are common, and may be associated with frailty owing to their physiological roles in homeostasis. This study assessed the association between frailty and electrolyte imbalances.

This cross-sectional study included older adults who underwent a comprehensive geriatric assessment in an outpatient clinic of a university hospital. According to Fried's criteria, associations between each electrolyte abnormality (hypo/hypernatremia, hypo/hyperkalemia, hypo/hypermagnesemia, hypo/hyperphosphatemia, hypo/hypercalcemia) and frailty group (frail, prefrail, robust) were investigated.

Of the 1722 patients included, 71% were females, and the mean age was 84 ± 8 years. Frailty was found in 1066 (62%) patients, while 488 (28%) were prefrail, and 168 (10%) were in the robust group. Hyponatremia rates in frailty, prefrailty, and no frailty groups were 10.6%, 5.9%, and 2.4%, respectively (p < 0.001). Hypomagnesemia rates were 18.1%, 11.1%, and 6.5%, respectively (p < 0.001). The prevalence of other electrolyte abnormalities was comparable between groups. Frailty was associated with hypomagnesemia when compared to pre-frailty, also after adjustments for age, sex, drug count, MNA score, Charlson comorbidity index, Lawton and Bartel scores (OR:1.63, 95% CI 1.03-2.57, p = 0.037). Compared to patients without frailty, those who had frailty were more likely to have hyponatremia after adjusting for age and sex, but the significance was lost after the inclusion comorbidities, drug counts, daily living scores and the MNA score in the model. Other comparisons between groups were not significant after adjustments. Frail patients were more likely to have multiple electrolyte abnormalities. Multiple electrolyte abnormalities were not associated with worse frailty status than single abnormality after age- and sex-adjustment.

Hypomagnesemia and hyponatremia are common in older adults and are associated with frailty. Prevention or correction of these imbalances may improve frailty outcomes.