BP found to fluctuate with seasonal change
Cholesterol has been shown to reach its highest levels in the winter, and now hypertension treatment appears to be affected by seasonal influences as well. A five-year analysis of records at 15 Veterans Administration (VA) hospitals revealed that drug therapy is less likely to restore normal BP in the winter than in the summer. This effect was observed even in warm regions.
“San Juan, Puerto Rico, is virtually equivalent to Anchorage, Alaska, as BP systematically worsens in the winter and improves in the summer,” stated lead investigator Ross D. Fletcher, MD, chief of staff at the VA Medical Center in Washington, D.C. Additional VA hospitals studied included those in New York, Chicago, and Los Angeles.
Every city reflected a significant variation in return to normal BP in winter compared with summer. The average difference was nearly 8%. Speculating on the reason, Dr. Fletcher said people tend to exercise less and gain weight in winter. He added that the clinical implication was for practitioners to be alert to the possible seasonal change and to step up therapy as needed. He presented his findings at the recent American Heart Association meeting in Orlando.
Two other new hypertension studies also contained useful information. In one, researchers reported that high BP significantly increases the risk of later disabilities in life functions, such as the ability to bathe oneself, walk up and down stairs, or lift heavy objects (Hypertension. 2007;50:1026-1032). This was particularly true for women. In the other study, (published online in Hypertension before print, November 26, 2007), nocturnal BP was better than daytime BP in predicting coronary heart disease, stroke, and death.