Effect of environmental exposure to hydrogen sulfide on central nervous system and respiratory function: a systematic review of human studies.

BACKGROUND: Assessment of the health effects of low-level exposure to hydrogen sulfide (H2S) on humans through experiments, industrial, and community studies has shown inconsistent results. OBJECTIVE: To critically appraise available studies investigating the effect of H2S on the central nervous system (CNS) and on respiratory function. METHODS: A search was conducted in 16 databases for articles published between January 1980 and July 2014. Two researchers independently evaluated potentially relevant papers based on a set of inclusion/exclusion criteria. RESULTS: Twenty-seven articles met the inclusion criteria: 6 experimental, 12 industry-based studies, and 10 community-based studies (one article included both experimental and industry-based studies). The results of the systematic review varied by study setting and quality. Several community-based studies reported associations between day-to-day variations in H2S levels and health outcomes among patients with chronic respiratory conditions. However, evidence from the largest and better-designed community-based studies did not support that chronic, ambient H2S exposure has health effects on the CNS or respiratory function. Results from industry-based studies varied, reflecting the diversity of settings and the broad range of H2S exposures. Most studies did not have individual measurements of H2S exposure. DISCUSSION: The results across studies were inconsistent, justifying the need for further research.

Malnutrition in the nursing home.

PURPOSE OF REVIEW: Malnutrition in the nursing home is increasingly recognized as a major international research priority, given the expanding geriatric populations, serious consequences, and challenges conducting research in nursing homes. This review examines the recent literature and suggests implications for research and practice. RECENT FINDINGS: Across the recent studies, approximately 20% of nursing home residents had some form of malnutrition. However, malnutrition definitions were variable and prevalence ranged from 1.5 to 66.5%. Depression, cognitive impairment, functional impairment, and swallowing difficulty were consistently associated with malnutrition. Mortality was the major consequence of malnutrition among nursing home residents, whereas higher BMIs had lower risks of mortality. Beneficial interventions to reduce malnutrition in the nursing home included dietary supplements, greater resident role in food choice, and staff training programs. SUMMARY: To truly tackle the issue of malnutrition in the nursing home setting, a consistent definition is needed. We strongly recommend that an expert consensus panel identify a standard set of measures to more accurately compare the prevalence across countries. Given the mortality consequences of malnutrition and the paucity of intervention studies, research on interventions for malnutrition in the nursing home needs to be a higher priority for facilities, researchers, and funding agencies.