ARGININE-VASOPRESSIN LEVELS IN NURSING-HOME RESIDENTS WITH NIGHTTIME URINARY-INCONTINENCE

OBJECTIVES: To examine the relationship between diurnal urine volume a nd plasma arginine vasopressin levels (AVP) in nursing home residents with nighttime urinary incontinence and a comparison group of frail bu t nondemented, continent geriatric board and care residents. DESIGN: C ase series. SETTING: Four nursing homes and two board and care facilit ies. PARTICIPANTS: Sixty-two nursing home residents and 27 board and c are residents. MEASUREMENTS: Daytime (7:00 a.m. to 7:00 p.m.) and nigh ttime (7:00 p.m. to 7:00 a.m.) urine volumes of incontinent nursing ho me residents were measured over 3 days and 3 nights by reweighing prew eighed adults diapers and toileting inserts emptied by research staff for the comparison group. AVP levels were drawn in the early morning ( 5:00 a.m. to 7:00 a.m.) before subjects arose and in the evening after an hour of lying in bed (8:00 p.m. to 11:00 p.m.), and plasma levels were determined by radioimmunoassay. RESULTS: Half of the nursing home residents and 82% of the comparison group had night/total urine volum e ratios greater than or equal to 50%. Forty-nine percent of the total of 89 subjects had undetectable morning AVP levels, 61% had undetecta ble evening AVP levels, and 42% had undetectable AVP levels in both mo rning and evening. There were no significant differences in AVP levels between those with night/total urine volume ratios greater than or eq ual to 50% and <50% in either the nursing home or comparison groups th ough the small number of comparison group subjects with ratios < 50% m ay have limited our statistical power to detect differences. CONCLUSIO N: Our data suggest that a substantial proportion of both nursing home residents with nighttime incontinence and frail geriatric patients wi th a reversal of the normal diurnal pattern of urine excretion have an accompanying deficiency in AVP production and/or secretion. More deta iled physiologic studies are needed to understand better the pathophys iology of geriatric nocturia and nighttime incontinence and the role t hat AVP deficiency may play in these conditions. Until such studies ar e carried out, we do not recommend the routine use of exogenous AVP fo r geriatric patients with unexplained nocturnal polyuria.