A global analysis has shown that the prevalence of diabetes has increased since 1980 and reached a whopping 347 million by 2008. While Harvard researchers say this boom was due to the aging population and population growth, they concluded that preventive interventions are necessary to manage and detect patients with this comordibity, according to the study published online June 25 in the Lancet.

“Hyperglycemia and diabetes are important causes of mortality and morbidity worldwide, through both direct clinical squeal and increased mortality from cardiovascular and kidney diseases,” Goodarz Danaei, MD, of the Harvard School of Public Health in Boston, and colleagues wrote. “With rising overweight and obesity, concern has risen about a global diabetes epidemic, with harmful effects on life expectancy and healthcare costs."

Because previous studies have not looked at global diabetes trends, Danaei and colleagues analyzed surveys and epidemiological studies from the WHO Global InfoBase that included 370 country-years and 2.7 million participants to estimate the trends in mean fasting plasma glucose (FPG) and diabetes prevalence for adults age 25 years and older in 199 countries and territories. The researchers used a Bayesian hierarchical model to estimate mean FPG and its uncertainty by sex, age, country and year.

An FPG was used as the primary measure of glycemia because it was utilized in more population-based studies and diabetes prevalence was a secondary outcome. The American Diabetes Association definition of diabetes was used: a FPG equal to 7 mmol/L or greater, diagnosis or use of glucose lowering drugs.

Of the studies included, 71 percent reported mean FPG or diabetes prevalence based on FPG, while others used post-prandial glucose of HbA_1c. In 2008, the age-standardized mean FPG was reported to be 5.50 mmol/L for men and 5.42 mmol/L for women, an estimated 0.07 mmol/L increase per decade since 1980.

The age-standardized prevalence of diabetes was reported to be 9.8 percent in men and 9.2 percent in women in 2008. The researchers reported that 40 percent of the people with diabetes were from China and India, 10 percent were from the U.S. and Russia and 12 percent were from Brazil, Pakistan, Indonesia, Japan and Mexico.

In 1980, the age-standardized prevalence of diabetes was 8.3 percent in men and 7.5 percent in women. The authors said that 70 percent of the 194 million cases of diabetes between 1980 and 2008 were attributable to population growth and aging. The additional 30 percent were due to a rise in age-specific prevalence.

FPG in men was lowest in sub-Saharan Africa (5.27 mmol/L), followed by east and southeast Asia and Asia-Pacific. Women in Asia-Pacific had the lowest mean FPG (5.17 mmol/L), followed by sub-Saharan Africa and east and southeast Asia. In 2008, Oceania had the highest mean FPG and diabetes prevalence of any region in 2008 for both men and women. These numbers were 6.09 mmol/L for men and 6.08 mmol/L for women.

Mean FPG and diabetes was also high for both sexes in south Asia, Latin America and the Caribbean. The authors noted that FPG increased or remained unchanged in almost every region between 1980 and 2008.

“Our systematic analysis shows that glycemia and diabetes are a rising global hazard, with the number of adults with diabetes having more than doubled over nearly three decades,” the authors wrote.

The researchers said that a limitation to the study was the fact that many country-years did not have data, especially in the 1980s and in some low-income and middle-income countries.

“Specifically, although effective drugs to lower blood pressure and cholesterol are increasingly used for primary prevention of cardiovascular disease in high-income countries, the use of specific drugs for primary prevention and the targets and intensity of glycemic management, are still being investigated.

“Therefore, primary prevention of dysglycemia will need weight control, physical activity and improved diet quality,” the authors wrote.

However, Danaei and colleagues noted that these interventions will be difficult to implement in populations and most likely will not impact the incidence of diabetes in the short term. The authors concluded that countries must develop initiatives to improve the detection and management of diabetes.