Bacteriuria and vitamin D deficiency: a cross sectional study of 385 nursing home residents.

BACKGROUND: Up to half of elderly people at nursing homes have asymptomatic bacteriuria, and concentrations of 25-hydroxyvitamin D (25OHD) are generally low. Vitamin D is a modulator of the immune system and involved in protection of the epithelium in the urinary tract as well. The objective was to determine a possible association between bacteriuria and vitamin D deficiency among elderly people at nursing homes. METHODS: Cross-sectional study: Voided urine specimens and blood samples for cultivation and analysis of 25OHD were collected from elderly people at nursing homes in Sweden. Exclusion criteria were: urinary catheter, ongoing antibiotic treatment, incontinence or dementia too severe to provide a voided urine specimen or leave a blood sample, unwillingness to participate or terminal illness. Urine cultures and serum 25OHD concentrations were outcome measures and the association of bacteriuria with vitamin D deficiency was determined by logistic regression. RESULTS: Twenty-two nursing homes participated and 385 of 901elderly people provided voided urine specimens and blood samples. The mean age was 87 (SD 6.7), 69% women, 19% received vitamin D supplement, 13% had diabetes mellitus, and 54% were diagnosed with dementia. There was significant growth of potentially pathogenic bacteria in 32% (123/385) of voided urine specimens. Escherichia coli were present in 83% of positive urine cultures. The mean concentration of 25OHD in serum was 35 nmol/L (SD 21). Thirty-seven per cent (143/385) had 25OHD < 25 nmol/L, and 3.1% (12/385) 25OHD < 12.5 nmol/L. No association between bacteriuria and 25OHD < 25 nmol/L, OR 1.4 (0.86-2.3; p = 0.18) adjusted for age, gender, diabetes mellitus and dementia was found. However, if using 25OHD < 12.5 nmol/L as a cut-off for vitamin D deficiency the adjusted odds-ratio was 4.4 (1.1-17; p = 0.031). CONCLUSIONS: Bacteriuria and vitamin D deficiency was common. No association between bacteriuria and 25OHD < 25 nmol/L was found. If using 25OHD < 12.5 nmol/L as cut-off for vitamin D deficiency there was an association. However, this has to be interpreted with caution as causality cannot be evaluated as well as only few residents had 25OHD < 12.5 nmol/L.

Vitamin D deficiency was common among nursing home residents and associated with dementia: a cross sectional study of 545 Swedish nursing home residents.

BACKGROUND: Residents of nursing homes may have low 25-hydroxyvitamin D (25OHD) concentrations. Associations between vitamin D and cognitive performance, dementia and susceptibility to infections are not clearly established. The aim of this study was to investigate the prevalence of vitamin D deficiency and to identify associated factors among residents of nursing homes for elderly. METHODS: In this cross-sectional study blood samples for analysis of 25OHD were collected from all participating residents of Swedish nursing homes for the elderly from January to March 2012. EXCLUSION CRITERIA: dementia too severe to collect a blood test, terminally ill or refusing participation. OUTCOME MEASURES: Serum 25OHD concentrations. Logistic regression to evaluate factors associated with vitamin D deficiency (25OHD < 25 nmol/L). RESULTS: Blood samples were obtained from 545 of 901 residents of 22 nursing homes. Mean age 86 years (SD 6.9), 68% were women. Prevalence of vitamin D supplementation 17%, dementia 55%, lack of appetite ≥3 months 45% and any antibiotic treatment during the last 6 months 30%. Serum 25OHD concentrations: mean 34 nmol/L (SD 21, median 27, range 4-125), 82% (448/545) had 25OHD < 50 nmol/L and 41% (224/545) had 25OHD < 25 nmol/L. Adjusted OR (95% CI; p-value) for possible predictors of vitamin D deficiency (25OHD < 25 nmol/L): vitamin D supplementation 0.075 (0.031-0.18; p < 0.001), lack of appetite ≥3 months 0.75 (0.50-1.1; p = 0.15), hours outdoors/week 0.99 (0.96-1.0; p = 0.62), Fitzpatrick skin phototype (4-6) 0.69 (0.44-1.1; p = 0.12); dementia 2.3 (1.5-3.4; p < 0.001) and antibiotics last 6 months 1.6 (1.1-2.6; p < 0.029), adjusted for age and gender. CONCLUSIONS: Vitamin D deficiency was common among nursing home residents and strongly associated with dementia. Regardless of causality or not, it is important to be alert for vitamin D deficiency in nursing homes residents with dementia. As expected vitamin D supplementation was associated with less vitamin D deficiency, however lack of appetite, staying outdoors and skin phototype were not significant predictors. Antibiotic treatments during the last 6 months were associated with vitamin D deficiency, potentially supporting the hypothesis that vitamin D deficiency is associated with infections.