Incidence of hypertension in the Framingham Study.

Incidence and trends in incidence of definite hypertension were analyzed based on 30 years follow-up of 5,209 subjects in the Framingham Heart Study cohort. Based on pooling of 15 two-year periods, hypertension incidence per biennium increased with age in men from 3.3 per cent at ages 30-39 to 6.2 per cent at ages 70-79, and in women from 1.5 per cent at ages 30-39 to 8.6 per cent at ages 70-79. No consistent trend in incidence rates was evident for either sex from the 1950s through the 1970s. The proportion of hypertensive subjects receiving antihypertensive medication has increased since 1954-58 and exceeded 80 per cent for both men and women ages 60-89 years in 1979-81. Incidence data presented in this report may serve as a baseline for assessing the impact of future public health efforts in the primary prevention of hypertension.     

Changing mortality patterns in Nauruans: an example of epidemiological transition.

An analysis of mortality data for the years 1982-5 was carried out for the Micronesian population (aged 15 years and over) of the central Pacific Island, Nauru. Among males, the most common causes of death were circulatory system disorders (33.3%), accidents (25.2%), and diabetes mellitus (12.1%). The majority of accidents occurred in the 15-34 year age group and involved motor vehicles. Among females, neoplasms (almost all lung and cervix) (22.4%), circulatory system disorders (20.7%), and diabetes mellitus (17.2%) were the most common causes of death. When accidents are excluded, 59.4% of deaths were in persons with diabetes. Compared with Australia, mortality rates in almost all age groups were at least five times higher for males and females for a comparable period. Nauruan life expectancy (39.5 years for men and 48.5 years for women) is one of the lowest in the world. These data confirm the high mortality associated with diabetes mellitus in Nauruans as evidenced in earlier studies. Modernization of this society through the affluence acquired by the mining of phosphate has led to serious public health problems relating to non-communicable diseases so that the mortality trends now mirror those of developed societies.     

Growth and development in rats and deficiency of magnesium and pyridoxine

Eight-eight female weanling Sprague-Dawley rats were fed diets containing either 650 or 150 mg magnesium/kg diet and 7.0 or 3.5 mg pyridoxine-HCl/kg diet, in a 2 x 2 factorial arrangement, during growth, gestation, and lactation. The objective of the study was to determine whether concurrent dietary deficiencies of magnesium and pyridoxine were synergistic, additive, or antagonistic with regards to effects on reproductive performance, growth, and development of offspring, and tissue content of magnesium and calcium. Body weight of dams and pups was not different between groups until day 9 of lactation, at which point those animals in either low magnesium group weighed less than the other. Litter size and birth weight were not different. Development, as measured by timing of unfolding of the external ear, opening of both eyes, and clinical emergence of incisors, was delayed in pups from litters in the low magnesium groups. A synergistic effect on delay of onset of ear unfolding by deficiency of both magnesium and pyridoxine was observed. Calcium content of heart and kidney from dams was increased in the low magnesium groups. Renal calcium was not further increased by the level of pyridoxine deficiency in this study. The calcium to magnesium ratio in heart from pups was higher in those from litters in the low magnesium and pyridoxine group than in the others. Results indicate that simultaneous deficiencies of magnesium and pyridoxine may impair function synergistically. Because these two nutrients are often reported to be presented in inadequate amounts in diets of women in their reproductive years, the potential exists for impaired reproductive success.