Cardiovascular disease accounts for about one-third of all premature deaths (before the age of 70 years), in Cuba. Yet the relevance of major risk factors, including blood pressure, diabetes and body mass index (BMI)* in this population were unclear, since very few studies have been carried out in Latin America. NDPH researchers, in partnership with Cuban researchers from the National Institute of Cardiology and Cardiovascular Surgery in Havana, have investigated this through a prospective study involving over 125,000 men and women aged 30-79 from across five Cuban provinces. The results are published today in BMC Public Health.
The study participants were recruited between 1996-2002, and had their height, weight and blood pressure measured. They were then followed for an average of 17 years until 1 January 2017, through electronic linkage to national death registries.
During this time, 4,112 cardiovascular deaths occurred in the study population, including 2,032 heart attacks and 832 strokes. The results of the study showed:
- Cardiovascular death was positively associated with high blood pressure, diabetes and high BMI.
- The association between higher blood pressure and increased risk of cardiovascular death extended throughout the blood pressure range, with no threshold down to at least 120 mmHg. Overall, each 20 mmHg higher blood pressure approximately doubled the risk of cardiovascular death.
- Above a BMI of 22.5 kg/m2 (an ‘ideal’ weight), each 10 kg/m2 higher BMI approximately doubled the risk of cardiovascular death.
- Around 5% of the participants had diabetes, which doubled their risk of cardiovascular death.
- High blood pressure, diabetes and high BMI accounted for 27%, 14%, and 16% of cardiovascular deaths, respectively.
These results suggest that, of the entire population of people aged 35-79 years in Cuba, in 2015 around 5,000 excess deaths from cardiovascular disease were caused by high blood pressure; 2,600 excess deaths were due to diabetes, and 3,000 excess deaths were due to raised BMI.
The association between cardiovascular death and high BMI was significantly weakened when adjusted for the participant’s blood pressure. This suggests that the risk of cardiovascular death could be reduced for many by using treatments that control blood pressure, even in the absence of other cardioprotective medications, such as statins. Previous work by these researchers, however, suggests that many Cuban adults with high blood pressure are not being treated with antihypertensives, and only about a third of treated patients have controlled blood pressure.
Professor Sarah Lewington, one of the lead researchers from NDPH, said: ‘This large prospective study provides direct evidence for the effect of blood pressure, diabetes and BMI on cardiovascular mortality in Cuba.’ According to Dr Nurys Armas, an author from the National Institute of Cardiology and Cardiovascular Surgery, Havana: ‘Healthcare programmes to increase the availability and use of blood pressure-lowering medication are being delivered in Cuba’, but author Dr Ben Lacey added: ‘Public health programmes also need to address the increasing prevalence of obesity and diabetes in Cuba, as well as other major risk factors for cardiovascular disease, in particular smoking.’
(*BMI is a measure of body mass relative to a person’s size, calculated by dividing a person’s weight in kilograms by the square of their height in metres.)