Just an update, to let you all know....

Hello dear readers, friends and family!

Summer is almost over, and fall and cooler weather is on the horizon...so keep this information in mind:    Falling temperatures may be accompanied by rising numbers of deaths from stroke, especially among older people, researchers find.

That’s the word from Brazilian researchers who found that in the case of older people the incidence of stroke associated with colder weather was higher among women.

"At the beginning of the study, we thought pronounced temperature variability, whether in a warmer or cooler direction, would correlate similarly with both stroke subtypes (ischemic and hemorrhagic) . In other words, there would be more deaths from both subtypes on very cold or very hot days,” said São Paulo, Brazil, geographer Priscilla Venâncio Ikefuti. “That's not what we found, however. In the case of hemorrhagic stroke, cold is a far more important factor, especially for women.”

In the case of hemorrhagic stroke (the most severe subtype), lower temperatures were found to be a risk factor for both men and women, especially below 50 degrees Fahrenheit. Among over-65s, lower temperatures represented a higher risk of hemorrhagic stroke for women. This finding was unexpected and surprised the researchers.

The finding that stroke is a more frequent cause of death among over-65s could be explained as due to diminished metabolism in the elderly. In response to changes in temperature, older people are less capable of maintaining homeostasis, the tendency to resist change in order to maintain constant physiological conditions necessary to survival.

"We also found that for all cases of stroke, and hemorrhagic stroke in particular, women are more vulnerable than men," said Ikefuti. "The data also show that stroke mortality is higher among women on average, albeit slightly. The relative risk of having a stroke in correlation with mean temperature variations was also higher for women than men. Similarly, lower mean temperatures affected women more than men in respect of both stroke subtypes."

Stress due to cold, she explained, results in increased blood viscosity and platelet count, raising arterial blood pressure enough to pose the threat of hemorrhagic stroke.

According to Alfesio Luis Ferreira Braga, a professor at Unisantos who co-authored the study, another important explanation for the higher risk of stroke among women is menopause, when the body produces less estrogen, the hormone that stimulates or controls the development and maintenance of female characteristics. Lack of estrogen during menopause subjects women to a higher risk of vascular disease, among several other conditions.

"Our study contributes to the understanding of the impact of temperature on stroke mortality in a tropical country, where temperature might be assumed not to be a concern regarding the risk of stroke. It proves that isn't the case, at least not in São Paulo City," Braga said.

"Although the city is in a subtropical region, so that mean temperatures are higher than in countries with a temperate climate, substantial daily temperature variations and the occurrence of cold fronts or heatwaves are indeed risk factors for stroke, especially among the elderly, and above all among women."

The study was published in the International Journal of Biometeorology.