Serum levels of total and free IGF-I and IGFBP-3 are increased and maintained in long-term training.

The goals of this study were to determine whether the long-term training regimens experienced by competitive collegiate swimmers would result in altered levels of total and free serum insulin-like growth factor I (IGF-I) as well as IGF-binding proteins (BP) IGFBP-1 and -3. Two male (Teams 1M and 2M) and one female (Team 2F) teams were studied at the start of training, after 2 mo of training, after 4 mo (2-4 mo had the highest volume of training), after 5 mo (near the end of tapering; only for Team 1M), and several days after training was over. For Team 1M, total IGF-I concentrations were increased by 76% after 4 mo and were subsequently maintained at this level. Total IGF-I responses were more variable for Teams 2F and 2M. Free IGF-I levels were increased nearly twofold for all teams at 2 mo and were maintained or increased further with subsequent training. Only the levels of free IGF-I for Team 1M returned to pretraining values after training had ended. Training had little effect on IGFBP-1 levels. For all teams, serum IGFBP-3 was elevated by 4 mo of training (for Team 2F it was increased at 2 mo) by 30-97% and remained at these higher levels thereafter. The ratio of total IGF-I to IGFBP-3 was not increased by training in any group. These data indicate that serum levels of total and free IGF-I and total IGFBP-3 can be increased with intense training and maintained with reduced training (tapering). The findings show that changes in free IGF-I levels are not accounted for by alterations in the total IGF-I/IGFBP-3 complex or in IGFBP-3 levels and indicate that there are other important determinants of free IGF-I.

Blood pressure differences in older black and white long-term vegetarians and nonvegetarians.

The vegetarian diet has been associated with lower blood pressure (BP) in elderly white Americans. This study was undertaken to determine whether or not long-term adherence (at least 5 years) to a plant-based diet is similarly related to lower BP in older black Americans, a group exhibiting significant risk for hypertension (HT). Anthropometric characteristics, nutrient intake, and resting systolic and diastolic BP were measured in older black vegetarians (n = 27, age = 69.3 +/- 1.7 years), black nonvegetarians (n = 37, age = 65.4 +/- 1.2 years), white vegetarians (n = 85, age = 66.7 +/- 1.0 years), and white nonvegetarians (n = 54, age = 65.2 +/- 0.9 years). Older black vegetarians were significantly leaner and exhibited lower average systolic BP (131.4/76.8 mm Hg) and less hypertension than the black omnivores (141.6/76.2 mm Hg), but had significantly higher average BP than either dietary group of older white adults (vegetarians: 120.9/66.7 mm Hg; nonvegetarians: 122.8/67.6 mm Hg). These data suggest that long-term adherence to a vegetarian diet by older black Americans may afford some protection against hypertension, but in comparison to older white adults, does not completely offset their apparently greater susceptibility to untoward elevation of BP.

Blood pressure and anthropometric differences in regularly exercising and nonexercising black adults.

Few studies have examined the relationship between exercise and BP in Black adults, a population with substantial risk for hypertension. This pilot study was undertaken to examine BP, anthropometric characteristics, dietary intake, and resting pulse rate by level of exercise participation in a group of Black Seventh Day Adventists. Subjects were classified as regular exercisers (n = 54, age = 54.6 yrs) if they reported at least two exercise sessions per week (x = 4.0 times per week) lasting a minimum of 20 minutes each, in which they engaged in vigorous exercise. Nonexercisers (n = 60, age = 56.2 yrs) were those who reported participation in such exercise no more than once per week (x = 0.1 times per week). There were no group differences in dietary intake of any macro or micronutrients, but exercisers exhibited significantly lower body mass index, waist circumference, triceps skinfold thickness, and resting pulse rate. Forty-two percent of the nonexercisers were confirmed hypertensives compared to only 20 percent of the exercisers. Age and gender-adjusted BP was significantly lower in the exercisers (BP = 123.8/73.4 mm Hg) compared to the nonexercisers (BP = 133.5/77.1 mm Hg). After adjustment for anthropometric differences, the systolic BP of the exercisers remained approximately 8 mm Hg lower than their nonexercising counterparts. These data suggest that participation in vigorous exercise is favorably related to blood pressure and may attenuate the risk of hypertension in Black Seventh Day Adventists.

Relation between vegetarian/nonvegetarian diets and blood pressure in black and white adults.

We examined the possible interaction of race and diet on blood pressure (BP) in volunteer Black Seventh Day Adventists compared to volunteer White church members. Height, weight, waist and hip circumference, and resting seated BP were recorded in Black vegetarians (n = 55; age: 54.7 +/- 16.9 yrs), Black nonvegetarians (n = 59; 56.1 +/- 14.1 yrs), White vegetarians (n = 164; 52.2 +/- 16.7 yrs), and White nonvegetarians (n = 100; 52.6 +/- 15.6 yrs) attending a regional conference. Forty-four percent of the Black nonvegetarians were medicated hypertensives, compared to only 18 percent of the Black vegetarians, 7 percent of the White vegetarians, and 22 percent of the White nonvegetarians. Black vegetarians exhibited lower age and sex-adjusted systolic BP (means = 122.9/74.4 mm Hg) than Black nonvegetarians (means = 132.2/75.9 mm Hg). After further adjusting BP for body mass index and waist/hip ratio, the systolic BP among Black vegetarians remained lower (122.8) than Black nonvegetarians (129.7) but higher than that of the Whites who showed no diet-related BP differences.