We report an age-adjusted prevalence of diabetes of 20% in this population, which is higher than that reported in similar populations for both men and women within the country or in the region 2,6,10–13
. In 2005, Wijewardena et al
. reported prevalences of 14.2 and 13.5% in 30- to 65-year-old men and women from five provinces of Sri Lanka 6
. Katulanda et al
. (in 2006) estimated the age- and sex-standardized prevalence of diabetes as 16.4% for the urban adult Sri Lankan population over 20 years based on the 75-g oral glucose tolerance test 10
. Ramachandran et al
. reported an age-standardized prevalence of diabetes of 12.1% in a study conducted in six major cities covering all regions of India 11
. In urban areas of Bangladesh, the prevalence of diabetes was estimated to be 8.0% 12
. In urban Pakistan, the prevalence of diabetes was 6% 13
. In Nepal, the prevalences of diabetes in urban and rural areas were estimated to be 15 and 3%, respectively 14
. Our study, being the most recent and comprising an older population from an urban area, may explain the differences in the estimates between the studies. These results may also be a reflection of the epidemiologic transition that Sri Lanka has experienced earlier than other countries in the South Asian region and the increase in the number of patients with diabetes projected in the region by 2030 by the International Diabetes Federation 2
. The prevalence of diabetes we report is likely to be an underestimate of the actual prevalence, as fasting plasma glucose levels were used in the classification of subjects with diabetes in this study instead of the 2-h plasma glucose test that is considered to be more sensitive to diagnose diabetes, especially in older populations 15
Of the 474 subjects who had a history of diabetes, all were on treatment except for nine men and nine women. Optimal glycaemic control, defined as a HbA1c
< 48 mmol/mol (6.5%), was achieved in only 48 men (24.7%) and 65 women (23.2%), highlighting the need for good management of patients. Although national best practice guidelines for the treatment of diabetes are available 16
, they are not adhered to on a routine basis. In Sri Lanka, the government provides free healthcare services and medication. Sometimes there are shortages of drugs in government hospitals and patients have to purchase these drugs from the private sector as out-of-pocket expenses. In government hospitals, HbA1c
assays are not routinely performed. As some patients find it difficult to afford these tests from the private sector, there is a reluctance of physicians to order them.
In our study, there were 121 men and 142 women who had undetected diabetes, fasting blood glucose ≥ 7 mmol/l and/or an HbA1c
≥ 48 mmol/mol (6.5%), comprising one third of all patients with diabetes (35.7%) in the community. Katulanda et al
. reported similar results; i.e. that 36% of all patients with diabetes were undetected 10
. Impaired fasting glycaemia was prevalent in 47.5% of men and 43.9% of women (45.5% of the total population). Wijewardena et al
., using fasting plasma glucose of between 6.1 and 7 mmol/l as the cut-off, reported impaired fasting glycaemia in 14.2% of the men and 14.1% of the women in their study 6
. Katulanda et al
. reported a pre-diabetes prevalence of 11.5% (13.6% for men and 11.0% for women) in the adult Sri Lankan population over 20 years of age 10
; pre-diabetes was defined as impaired fasting glucose or impaired glucose tolerance or both. The high prevalence of impaired fasting glucose we report is probably attributable to our study population being an older urban population. Selecting an older urban adult population for our study was deliberate. Chronic diseases such as diabetes mellitus are more likely to emerge for the first time in this age group. Being urban would increase its prevalence. We are consistently following up this cohort for any siginificant outcome events and the study team provides long-term medical care for those who are diagnosed as having any chronic disease condition. The size of the study population and its geographical distribution make it possible to provide follow-up care even under low-resource settings. Katulanda et al
. in their study have covered a large geographic proportion of the country, both urban and rural, but the study was not intended to follow up the participants after their initial investigations.
The prevalence of cardiovascular disease risk factors was higher in patients with diabetes as compared with those without diabetes among both men and women. Katulanda et al
. reported similar findings 10
. In the regression models, high BMI, high waist circumference, high blood pressure and hypercholesterolaemia significantly increased fasting plasma glucose concentration after adjusting for age, sex, family history of diabetes and smoking. All the above risk factors are modifiable risk factors; hence, it is important that individuals with these risk factors be identified early and necessary preventive strategies be implemented.
The burden of impaired glycaemia and diabetes in this population in absolute terms is a dilemma for public health professionals in designing and implementing control programmes. Although the sample in this study is from a restricted geographic area, which may be considered a limitation, our findings are similar to those reported from other studies of urban areas within the country and the region. The large number of known patients with diabetes with suboptimal control implies that even those identified as having diabetes do not have access to proper management, or that even those who do have access do not receive optimal clinical care. In the short term, the major considerations should focus on identifying patients with diabetes and providing them with optimal treatment. A concerted effort should be made to target effective interventions to the population with impaired fasting glucose, primarily aimed at modifying lifestyles. In the long term, health promotion activities to increase knowledge of, and to improve attitudes towards, diabetes should be focused on a mass scale starting at an early age. In Sri Lanka, screening programmes have commenced and a few intervention options are currently being field tested. Challenges in developing such strategies include identifying an effective delivery mechanism, especially when such programmes were non-existent.