Dog ownership and mental health among community-dwelling older adults: A systematic review.

BACKGROUND: The population is ageing, and psychiatric disorders are common in older people. Those are associated with worsened quality of life. Although the positive relationship between dog ownership and physical health has been documented, data on mental health are scarcer, especially in community-dwelling older adults. OBJECTIVE: We sought to establish whether owning a dog was associated with a lower number of symptoms of psychological disorders in community-dwelling older adults. METHODS: We conducted a systematic review of the literature published between January 2005 and December 2020. We analysed comparative studies of the level of insomnia and symptoms of depression and/or anxiety among community-dwelling dog owners aged 70 and over. RESULTS: The search identified 191 articles, of which 117 full texts were assessed for eligibility. Five cross-sectional studies and one before-after with control group study (assessing a total of 25,138 older adults) were included. The mean (range) NOS score (five studies) was 6.8/9 (5-9) and the EPOC score (one study) was 2/8. The association between the presence of a dog and depressive symptoms did not appear to be significant. Regular contact with a dog was associated with fewer symptoms of anxiety. None of the studies specifically examined sleep disorders. CONCLUSIONS: Although the presence of a dog did not appear to be related to the level of depressive symptoms among community-dwelling older adults, there might be a beneficial relationship with anxiety. Further investigation is needed - especially with regard to the type of dog and the type of relationship with the dog.

Physiological risk factors for severe high-altitude illness: a prospective cohort study.

RATIONALE: An increasing number of persons, exposed to high altitude for leisure, sport, or work, may suffer from severe high-altitude illness. OBJECTIVES: To assess, in a large cohort of subjects, the association between physiological parameters and the risk of altitude illness and their discrimination ability in a risk prediction model. METHODS: A total of 1,326 persons went through a hypoxic exercise test before a sojourn above 4,000 m. They were then monitored up at high altitude and classified as suffering from severe high-altitude illness (SHAI) or not. Analysis was stratified according to acetazolamide use. MEASUREMENTS AND MAIN RESULTS: Severe acute mountain sickness occurred in 314 (23.7%), high-altitude pulmonary edema in 22 (1.7%), and high-altitude cerebral edema in 13 (0.98%) patients. Among nonacetazolamide users (n = 917), main factors independently associated with SHAI were previous history of SHAI (adjusted odds ratios [aOR], 12.82; 95% confidence interval [CI], 6.95-23.66; P < 0.001), ascent greater than 400 m/day (aOR, 5.89; 95% CI, 3.78-9.16; P < 0.001), history of migraine (aOR, 2.28; 95% CI, 1.28-4.07; P = 0.005), ventilatory response to hypoxia at exercise less than 0.78 L/minute/kg (aOR, 6.68; 95% CI, 3.83-11.63; P < 0.001), and desaturation at exercise in hypoxia equal to or greater than 22% (aOR, 2.50; 95% CI, 1.52-4.11; P < 0.001). The last two parameters improved substantially the discrimination ability of the multivariate prediction model (C-statistic rose from 0.81 to 0.88; P < 0.001). Preventive use of acetazolamide reduced the relative risk of SHAI by 44%. CONCLUSIONS: In a large population of altitude visitors, chemosensitivity parameters (high desaturation and low ventilatory response to hypoxia at exercise) were independent predictors of severe high-altitude illness. They improved the discrimination ability of a risk prediction model.