To examine the relationship between diurnal urine volume and plasma arginine vasopressin levels (AVP) in nursing home residents with nighttime urinary incontinence and a comparison group of frail but nondemented, continent geriatric board and care residents.DESIGN:
Four nursing homes and two board and care facilities.PARTICIPANTS:
Sixty-two nursing home residents and 27 board and care residents.MEASUREMENTS:
Daytime (7:00 a.m. to 7:00 p.m.) and nighttime (7:00 p.m. to 7:00 a.m.) urine volumes of incontinent nursing home residents were measured over 3 days and 3 nights by reweighing preweighed 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 volume ratios ≥ 50%. Forty-nine percent of the total of 89 subjects had undetectable morning AVP levels, 61% had undetectable evening AVP levels, and 42% had undetectable AVP levels in both morning and evening. There were no significant differences in AVP levels between those with night/total urine volume ratios ≥ 50% and <50% in either the nursing home or comparison groups though the small number of comparison group subjects with ratios < 50% may have limited our statistical power to detect differences.CONCLUSION:
Our data suggest that a substantial proportion of both nursing home residents with nighttime incontinence and frail geriatric patients with a reversal of the normal diurnal pattern of urine excretion have an accompanying deficiency in AVP production and/or secretion. More detailed physiologic studies are needed to understand better the pathophysiology of geriatric nocturia and nighttime incontinence and the role that AVP deficiency may play in these conditions. Until such studies are carried out, we do not recommend the routine use of exogenous AVP for geriatric patients with unexplained nocturnal polyuria.