High-density lipoprotein cholesterol concentration and other serum lipids in an isolated island community free of coronary heart disease.

Fasting serum high-density lipoprotein (HDL) cholesterol, other lipid concentrations and related characteristics have been measured in 87% of 261 residents aged over 5 years on the small isolated island of Salt Cay, Turks and Caicos Isles. Only one subject, a hypertensive woman, had a major electrocardiographic Q wave abnormality, and none of the islanders had clinical coronary heart disease. These findings, together with local clinical experience indicated a low incidence of coronary heart disease in this community. Adult mean concentrations of HDL cholesterol (1.6 mmol/l) and serum total triglyceride (0.81 mmol/l) were relatively high and low respectively compared with those of men and women in North American communities. Unlike findings in North America, there was no significant sex difference in HDL cholesterol concentration apparent in adulthood and this was not explained by sex differences in alcohol consumption (positively correlated with HDL cholesterol in both sexes) or adiposity (negatively correlated with HDL cholesterol in men only). Residents who were recovering from an epidemic of mild upper respiratory infection had on average a 9% reduction in HDL cholesterol concentration compared with the remainder of the community. The lipoprotein lipid pattern in these people is consistent with a low cardiovascular risk status, and might account for the apparent absence of coronary heart disease on the island.

Some non-infective diseases endemic in the West Indies

The West Indies is one of the most diverse archipelagos in the world. Into the numerous islands, with varying features of geography and natural history, have poured Europeans, Africans, Indians and small numbers of other ethnic groups, almost completely displacing the original Amerindian inhabitants. They have brought with them characteristic cultures and customs which, although to some extent blended and modified have, however, retained their identity. Such diversity affords exceptional opportunities for studies of disease in relation to geography and to racial origins, studies which can throw light on many aetiological problems (AU)

Heights and weights of West Indian children with the sickle cell trait.

No consistent differences were found in mean heights and weights of 170 schoolchildren aged 6--12 years with the sickle cell trait and 1247 schoolchildren with normal haemoglobin living in Dominica and Jamaica.

Blood-pressure and mortality in a rural Jamaican community.

1065 men and women aged 35--64 years living in rural Jamaica were first examined in 1962--1963, re-examined 5 and 10 years later, and followed-up until 1976. Overall mortality in 13 years, taking into account blood-pressures at all 3 surveys, showed that mortality was significantly increased only at pressures above 180 mm Hg systolic or 110 mm Hg diastolic. It was estimated that without this degree of hypertension the total number of deaths between the ages of 45 and 69 years would have been reduced by about 17%. Unlike other reports, mortality showed no significant association with lower levels of blood-pressure; this difference may be due to a lower incidence in this community of coronary and cerebral thrombosis. The relation between blood-pressure and mortality cannot be assumed to be identical in populations with different profiles of cardiovascular pathology.

The metacarpal index in Jamaican children and adults.

The metacarpal index was measured in radiographs of the hands of 615 male and 667 female Jamaicans aged over two years. The index increased with age from two years to adulthood, and was greater in females than in males, and greater in the left hand than the right hand. Means and standard deviations of the index for the left hand are presented as standards. An index of 9.6 for males and 10.1 for females over the age of 13 years is suggested as the upper limit of normal (three standard deviations above the mean). These standards are higher than those previously reported, and are probably applicable to other black populations outside Jamaica.

Some non-infective diseases endemic in the West Indies.

The West Indies, and associated parts of the Caribbean area, are extremely diverse and afford interesting examples for the study of geographical medicine. Short accounts are given of some conditions whose aetiologies have been relatively recently clarified, including vomiting sickness of Jamaica, veno-occlusive disease of Jamaica, blackfat pulmonary fibrosis of Guyana, and epidemic acute glomerulonephritis of Trinidad. The aetiology of tropical sprue, which is common in Puerto Rico and absent from Jamaica remains to be explained although a hypothesis has been put forward. Further work is needed to establish the geographical distribution of idiopathic cardiomegaly and the spinal neuropathies and associated syndromes of retrobulbar neuritis and sensorineural deafness before their aetiologies can be understood.