Undiagnosed and diagnosed diabetes mellitus among hospitalised acute heart failure patients in Botswana

Objective:

The objective of this study was to determine the burden of diagnosed and undiagnosed type 2 diabetes mellitus among patients hospitalised with acute heart failure in Botswana.

Methods:

The study enrolled 193 consecutive patients admitted with acute heart failure to the medical wards at Princess Marina Hospital in Gaborone. Patients were classified as previously known diabetics, undiagnosed diabetics (glycated haemoglobin ≥ 6.5%) or as non-diabetics (glycated haemoglobin < 6.5%). Data on other comorbid conditions such as hypertension, atrial fibrillation, ischaemic heart disease, stroke, and renal failure were also collected.

Results:

The mean (SD) age of the participants was 54.2 (17.1) years and 53.9% were men. The percentage of known and undiagnosed diabetes mellitus was 15.5% and 12.4%, respectively. Diabetic patients were significantly more likely to have hypertension (77.8% vs 46.0%, p < 0.001), ischaemic heart disease (20.4% vs 5.0%, p < 0.001), chronic kidney disease (51.3% vs 23.0%, p  < 0.001), and stroke (20.4% vs 5.8%, p  < 0.01). In addition, diabetics were older than non-diabetics (61.0 years vs 51.6 years, p  < 0.001).

Conclusion:

About 27.9% of patients admitted with acute heart failure in Botswana had diabetes, and almost half of them presented with undiagnosed diabetes. These findings indicate that all hospitalised patients should be screened for diabetes.

Metabolic syndrome, or What you will: definitions and epidemiology

The metabolic syndrome is a clustering of risk factors which predispose an individual to cardiovascular morbidity and mortality. There is general consensus regarding the main components of the syndrome (glucose intolerance, obesity, raised blood pressure and dyslipidaemia [elevated triglycerides, low levels of high-density lipoprotein cholesterol]) but different definitions require different cut points and have different mandatory inclusion criteria. Although insulin resistance is considered a major pathological influence, only the World Health Organization (WHO) and European Group for the study of Insulin Resistance (EGIR) definitions include it amongst the diagnostic criteria and only the International Diabetes Federation (IDF) definition has waist circumference as a mandatory component. The prevalence of metabolic syndrome within individual cohorts varies with the definition used. Within each definition, the prevalence of metabolic syndrome increases with age and varies with gender and ethnicity. There is a lack of diagnostic concordance between different definitions. Only about 30% of people could be given the diagnosis of metabolic syndrome using most definitions, and about 3540% of people diagnosed with metabolic syndrome are only classified as such using one definition. There is currently debate regarding the validity of the term metabolic syndrome, but the presence of one cardiovascular risk factor should raise suspicion that additional risk factors may also be present and encourage investigation. Individual risk factors should be treated.