The Cuba Prospective Study
In Cuba, a quarter of men and a sixth of women die between the ages of 35 and 69, mainly from vascular, cancer, and respiratory causes. The Cuba Prospective Study is a cohort study of 146 556 adults aged 30 and over, investigating the effects of major risk factors for premature adult mortality in this population.
- Participants were recruited from the general population in five provinces of Cuba between 1996 and 2002.
- Participants were interviewed, measured and followed up for cause-speciﬁc mortality through electronic linkage to national death registries.
- Data collected included: age, sex, height, weight, blood pressure, marital status, skin colour, education, occupation, smoking, alcohol, and medical history.
- Between 2006 and 2008, 24 345 participants were re-surveyed. The repeat assessments are used to correct baseline measures for random error and real biological variation.
Childhood smoking and adult mortality
- A third of the current smokers had begun smoking regularly before age 15, and 4% had begun smoking regularly before age 10.
- Starting to smoke in childhood is much more dangerous than starting later: those who had started to smoke before age 15 had twice the risk of premature death (before age 70) of those who had never smoked, with even greater risks among those who had started to smoke before age 10.
- Among those who began smoking before age 15, approximately half would eventually be killed by their habit; quitting smoking before 40 (preferably well before 40) avoided more than 90% of the risk
Burden of hypertension and associated risks for cardiovascular mortality
- A third of participants had hypertension. Two-thirds of those participants had a previous diagnosis of hypertension, among whom three-quarters were receiving treatment. However, only about a third of treated patients had controlled blood pressure.
- The prevalence of hypertension was strongly related to age and was higher in men than women at younger ages but higher in women than men at older ages.
- Blood pressure was not well controlled in any subgroup, even in participants with previous cardiovascular disease.
- Uncontrolled hypertension approximately doubled mortality risk and was estimated to account for 20% of premature cardiovascular deaths in 2015.
Alcohol consumption and cause-specific mortality in Cuba: prospective study of 120,623 adults
News item: Alcohol consumption in Cuba
- Over two-fifths of men and a seventh of women were current alcohol drinkers, with a third of men and a twentieth of women drinking at least weekly; most alcohol consumption was from rum.
- All-cause mortality was positively and continuously associated with weekly alcohol consumption: each additional 35cl bottle of rum per week (110g of pure alcohol) was associated with ~10% higher risk of all-cause mortality.
- The major causes of excess mortality in weekly drinkers were cancer, vascular disease, and external causes.
- Non-drinkers had ~10% higher risk of all-cause mortality than those in the lowest category of weekly alcohol consumption (<1 bottle/week), but this association was almost completely attenuated on exclusion of early follow-up.
Body-mass index, blood pressure, diabetes and cardiovascular mortality in Cuba: prospective study of 146,556 participants
- 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.
- The association with BMI and cardiovascular mortality was almost completely attenuated following adjustment for the mediating effect of SBP.
The Cuba Prospective Study is funded through core funding to the Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU) from the UK Medical Research Council, the British Heart Foundation, Cancer Research UK, and the US CDC Foundation (with support from Amgen).
DATA ACCESS AND SHARING
The Cuba Prospective Study is a collaboration between CTSU and the Institute of Cardiology in Havana. Specific proposals for future collaboration or specific analyses, addressed to the Cuba-based or Oxford-based Principal Investigators (firstname.lastname@example.org), are welcomed. Any requests for the sharing of data will be considered according to the principles set out in NDPH’s data sharing policy.