Mean total cholesterol increased in East and Southeast Asia by 0.08 mmol/L per decade in men and by 0.09 mmol/L per decade in women, and was lowest in sub-Saharan Africa at 4.08 for men and 4.27 for women. Cholesterol levels in Japan, which were relatively low in 1980, were close to levels in Western Europe in 2008. Singapore and China also registered substantial increases, which investigators surmised resulted from dietary changes.
Globally, the news on blood pressure was also mixed. Mean, age-standardized, systolic blood pressure decreased by 0.8 mm Hg per decade in men and by 1.0 mm Hg per decade in women since 1980, with Western Europe, Australia, New Zealand, and North America seeing steep declines, according to a study of 5.4 million people aged 25 years and older in 199 countries. (Lancet 2011 Feb. 4 [doi:10.1016/S0140- 6736(10)62036-3])
However, blood pressure rose in the tropical Pacific, East Africa, and South and Southeast Asia for both sexes, and in West Africa for women in the same period.
Female systolic blood pressure was highest in some East and West African countries in 2008, with means of 135 mm Hg or greater – numbers that, the investigators noted, were not unlike those seen in Europe and North America at the beginning of the study period in 1980.
"The decline we have seen is [primarily] in high-income countries and also parts of Latin America, so really we are dividing the world into the high-income nations that are mitigating the effects, whether it’s through lower-salt foods, or the primary care system catching and medicating," Dr. Ezzati said. "Middle-income countries, such as those in Latin America, have shown that they can do it, too, but in lower-income countries the infrastructure is really absent."
In each paper, the teams noted that their findings were limited in some cases by data quality in some countries, particularly low- and middle-income countries for the early years of the study period. However, Dr. Ezzati noted, the three papers represented "a massive data collection exercise which has never been done before."
The good news on blood pressure and cholesterol, he said, should be interpreted with caution. With drug interventions, "we are either mitigating or delaying the effects of obesity – we don’t know," he said. "In the next 5-10 years, we have done all of these mitigating things but the obesity epidemic is so large and so serious it could result in diabetes being the overwhelming cardiovascular threat. In some sense [the] obesity-diabetes nexus is the wild card."
Dr. Ezzati and colleagues are now working on a diabetes study of similar global scope.
Two researchers reported holding stock in Johnson & Johnson and Pfizer.