Rising Epidemic of Diabetes and Hypertension in Asia

T here has been a global increase in the prevalence of diabetes, most dramatically in Asia. ^1,2 According to the 4^th Diabetes Atlas by the International Diabetes Federation the diabetes burden is estimated to rise to 87 million people in 2030 in India. ³ However, 2011 estimates of 62.4 and 77.2 million people with diabetes and prediabetes, respectively, reported by the Indian Council of Medical Research are significantly higher than those estimated by International Diabetes Federation previously. ¹ It appears the burden of diabetes is increasing so fast (prevalence numbers being revised every one to two years) that revising estimates for two to three decades is not useful, and it may be better to predict for the next 3–5 years. In addition, there has been an increase of 30-fold among urban India to 10-fold among rural India of hypertension in the past three and six decades, respectively. ⁴ It is also important to keep in mind that blood pressure estimations are based on normal blood pressure data from the West, and it is possible that Asians may be expected to have lower blood pressure due to lower body mass index, and thus the reported increase in prevalence is at best an underestimate. Above all, diabetes and hypertension co-exist and often together add to morbidity and mortality, especially from cardiovascular disease, and could result in a significant economic burden for the emerging economies.

In this issue of Diabetes Technology & Therapeutics, Joshi et al. ⁵ report their data (Screening India's Twin Epidemic [SITE] study) that involved 15,000 patients from urban and semi-urban outpatient clinics. The study involved eight provinces (states) in India and reports nearly half of the patients have hypertension and one-third have diabetes. In addition, the two diseases co-existed in about 20% of the patients. The prevalence of isolated diastolic hypertension was higher (11.4%) than isolated systolic hypertension (7.7%). This may in part be due to the demographics and age groups evaluated in the SITE study, where only 25% of the subjects were older than 60 years of age. The investigators did not evaluate all their patients but only those seen in the first hour of each clinic. It may have been better to evaluate the prevalence across the day to avoid bias of more patients with diabetes visiting the clinics in the first hour.

Late last year, Yang et al. ² reported nearly 97 million with diabetes and another 112 million with prediabetes in China. It appears that the Asian subcontinent is starting to see a steeper increase in prevalence of diabetes and/or hypertension despite the normal to borderline increase in body mass index. This increase has been related to a disproportionate increase in truncal obesity. The exact etiology of this increase is unknown, although it might be related to changing dietary habits (to the Western diets), lack of exercise, and urbanization of the populations involved. To avoid increasing morbidity and mortality from these diseases and the rising cost associated with these disorders, prevention strategies need to be implemented at all levels. New normative data for blood pressure may need to be determined among Asians. As mentioned above, it is less important to predict what may happen in the next 20–30 years as the revisions to the prevalence are being changed every 1–2 years. It may be more relevant to predict only for the next 5 years, so that the impact of preventative strategies undertaken can be evaluated.