High relative environmental humidity is associated with diabetes among elders living in Mediterranean islands

Abstract

BackgroundClimate variation has long been studied in relation to human health. The aim of the present work was to evaluate the relationship between environmental humidity, and air temperature with the prevalence of diabetes, among elderly islanders.MethodsDuring 2005–2011, 1959 elderly (aged 65 to 100 years) individuals from 13 Mediterranean islands were enrolled. Socio-demographic, clinical and lifestyle factors were assessed using standard procedures. Diabetes was defined as fasting blood glucose levels > 125 mg/dl. Relative environmental humidity was measured as a percentage of air moisture and mean daily temperature in degrees Celsius.ResultsFor the present analysis 713 men (74 ± 7 years) and 596 women (73 ± 7 years) with complete data were studied; 27% of both men and women had diabetes. The prevalence of diabetes was 42% in the elders living in high relative humidity areas (i.e., >70%) as compared with 24% among those living at low relative humidity residential areas (p < 0.001). After adjusting for age, sex and mean temperature, an increase in the area’s relative humidity by 1 degree, increased the likelihood of having diabetes by 12% (OR = 1.12, 95% CI 1.05 to 1.20). No significant association was observed between mean temperature and diabetes (OR = 0.97, 95% CI 0.74, 1.26).ConclusionsA considerable proportion of elderly, especially those living in high relative humidity areas, had diabetes. Further research is needed to confirm this observation and to understand the underlying mechanisms.

Environmental effects of ambient temperature and relative humidity on insulin pharmacodynamics in adults with type 1 diabetes mellitus

“…An epidemiological study conducted in the Mediterranean area suggested an increased prevalence of diabetes among the elderly population on islands with high relative environmental humidity when adjusted for ambient temperature. 16 Notably, high relative humidity often occurs in the presence of high ambient temperature, making it challenging to unravel their individual effects. 17 Individuals with diabetes appear to tolerate moist, warm air with more than 50% humidity less well than adults without diabetes.…”

“…The effects of relative humidity on insulin pharmacodynamics and pharmacokinetics are largely unexplored. An epidemiological study conducted in the Mediterranean area suggested an increased prevalence of diabetes among the elderly population on islands with high relative environmental humidity when adjusted for ambient temperature . Notably, high relative humidity often occurs in the presence of high ambient temperature, making it challenging to unravel their individual effects .…”

Associations of Relative Humidity and Lifestyles with Metabolic Syndrome among the Ecuadorian Adult Population: Ecuador National Health and Nutrition Survey (ENSANUT-ECU) 2012

“…The less humid mountainous regions on the other hand showed the lowest prevalence of obesity (<30%) and MetS (30-35%) compared to the rest of the country [20]. Another study showed a positive association between diabetes mellitus, central obesity, higher systolic blood pressure, and lower physical activity in elder residents of the Mediterranean islands living in high relative humidity areas [21]. In addition, sociodemographic characteristics, epidemiological transition, globalization, and changes in lifestyle patterns (i.e., reduced physical activity and increased consumption of macronutrients and alcohol, and smoking) may modify these associations [6,22].…”

Daily humidity oscillation regulates the circadian clock to influence plant physiology

“…This is in line with the early observations that insect activity cycles are influenced by the diurnal humidity fluctuations reported by Colin Pittendrigh, a founder of chronobiology, in his work on malaria-transmitting mosquitoes 19 . We also anticipate that our study in plants may lead to more in-depth investigation of humidity influences on mammalian physiology, as multiple studies have reported a correlation between humidity and disease susceptibility in humans 56 – 58 .…”