Medical consequences of global warming

Introduction > The global warming of the planet and its anthropogenic origin ore no longer debatable. Nevertheless, from a medical point of view, while the epidemiological consequences of the warming are rather well-known, the biological consequences ore still poorly documented. This is a good example of evolutionary (or darwinian) medicine. Methods > The research strategy of this systematic review is based on both PubMed during the period of 2000-2007 and several reviews articles for the period > 2000. Results > From a medical point of view, there ore four types of consequences. 1-The simple elevation of the average external temperature is accompanied by on increased global mortality and morbidity, the mortality/external temperature is a J curve, with the worm branch more pronounced than the cold one. A recent study on 50 different cities had confirmed that global, and more specifically cardiovascular mortalities were enhanced at the two extreme of the temperatures. 2-The acute heatwaves, such as that which happened in France in August 2003, hove been studied in detail by several groups. The mortality which was observed during the recent heatwaves was not compensated by harvesting, strongly suggesting that we were dealing with heat stroke, and that such an increased mortality was more reflecting the limits of our adaptational capacities than aggravation of a previously altered health status. 3-Climate changes have modified the repartition and virulence of pathogenic agents (dengue, malaria...) and above all their vectors. Such modifications were exponential and ore likely to reflect the biological properties of parasites. 4-Indirect consequences of global worming include variations in the hydraulic cycle, the new form of tropical hurricanes and many different changes affecting both biodiversity and ecosystems. They will likely result in on increased level of poverty. Discussion > These finding gave rise to several basic biological questions, rarely evoked, and that concern the limits of the adaptational capacities of human genome. our genome has indeed been shaped in the post by a rather cold environment which has acutely been modified. The immediate physiological regulation includes sweating and skin vasodilatation. The latter may strongly enhance the cardiac output which explains the heat-induced cardiac decompensation. Long term regulation depends upon the numerous mechanisms of uncoupling of the mitochondrial respiration. For the moment, the thermolytic mechanisms and their regulation were rather poorly documented.