Biomedical subjects

E C Van Beresteijn

Publications and source records attributed to E C Van Beresteijn.

4 recordsLinked to original sources

PubMed1992

Development and evaluation of an index to predict early postmenopausal bone loss.

An index to predict individual postmenopausal bone loss is presented. The index is developed by means of data from a 10-year prospective Norwegian study in which bone mass of the distal forearm was measured annually in 73 women. All the women were 47 years old and premenopausal at inclusion. Independent risk factors for postmenopausal bone loss were identified by applying multivariate regression analysis on anthropometric, biochemical, nutritional, and life-style variables measured at menopause. The analysis identified low body weight, reduced renal phosphate reabsorption, and smoking as significant independent risk factors, and by means of these three factors a predictive index for postmenopausal bone loss was developed. This index was validated by using data from a 10-year longitudinal Dutch study, in which bone mass of the proximal radius was measured annually in 86 women, aged between 49 and 57 years and perimenopausal at inclusion. We defined women with the highest index score as "high-risk persons." According to this definition approximately 25% of the perimenopausal women were classified as high-risk persons, and the estimated sensitivity/specificity/positive predictive power were 36%, 89%, and 74%, respectively, when used to select women with a postmenopausal bone loss above average. We conclude that the index may be helpful in identifying healthy perimenopausal women in whom bone mass measurements should be considered.

Female↗

PubMed1992

Habitual dietary calcium intake and blood pressure change around the menopause: a longitudinal study.

In a 10-year follow-up study, blood pressure and dietary intake were measured annually in 167 healthy perimenopausal normotensive women. Their initial ages ranged between 49 and 56 years and habitual calcium intake between 560 and 2580 mg/day (mean 1110 mg/day); they lived in the mixed rural/industrial community of Ede, the Netherlands. The longitudinal design provided an opportunity to study the 'natural history' of blood pressure and the effect of dietary calcium during and after the period of ovarian failure. For data analysis, person-time experience was divided into three menopausal periods. Based on years relative to menopause three menopausal cohorts were created starting 2 years before, 2 years after and 6 years after menopause, each was followed for 4 years. Changes in systolic (SBP) and diastolic blood pressure (DBP) during the menopausal periods were adjusted for change in body mass index and other relevant variables in multiple regression analysis. An average decline in SBP of 6 mm Hg was observed in the period of 2 years before menopause to 6 years after menopause, and an increase of almost 5 mm Hg in the period between 6 and 10 years after menopause. A significant change in DBP was not observed. Neither changes in, nor the absolute level of, calcium intake showed any relevant association with blood pressure change. Ovarian failure seems to reverse temporarily the increase in blood pressure due to aging. The results do not suggest that a habitual calcium intake exceeding 800-1000 mg/day (the current Recommended Daily Allowance for adults) is effective in preventing hypertension during the peri- and postmenopausal period.

Blood Pressure↗

PubMed1991

Inhibitory effect of dietary soybean protein vs. casein on magnesium absorption in rats.

The effects of casein and soybean protein on magnesium absorption and magnesium concentration in the femur were investigated in rats. Purified diets containing either casein or soybean protein and three concentrations of added magnesium (0.82, 1.64 or 2.46 mmol/100 g diet) were used. The isonitrogenous diets were carefully balanced for the different mineral concentrations in the protein preparations. Absolute and percent magnesium absorption and urinary magnesium excretion were significantly decreased in rats fed soybean protein when compared with casein, irrespective of the dietary concentration of added magnesium. The magnesium content of femur was significantly lower in rats fed soybean protein, but this effect was seen only when the diet contained 0.82 mmol magnesium/100 g diet. The addition of sodium phytate to the casein diets, to a concentration identical to that in the diets containing soybean protein as provided by the soybean protein preparation, produced similar effects on magnesium absorption as the diets containing soybean protein. These results indicate that soybean protein, when compared with casein, decreases magnesium absorption through its phytate component.

Animals↗

PubMed1990

Milk: does it affect blood pressure? A controlled intervention study.

In a double-blind trial, the effect on blood pressure of supplementation of normal milk (1180 mg Ca2+, 1650 mg K+ and 110 mg Mg2+ d-1) vs. 'mineral-poor' milk (95 mg Ca2+, 580 mg K+ and 10 mg Mg2+ d-1) was studied. Young healthy normotensive female students consumed one of the two supplements while on a low calcium diet (less than 500 mg Ca2+ d-1) for a period of 6 weeks. In both the normal milk- and 'mineral-poor' milk-supplemented groups systolic blood pressure decreased slightly. However, this decrease was persistently greater in the milk-supplemented group. The individual mean systolic blood pressure change during normal milk treatment (-4.1%) was significantly greater (P = 0.03) than that during 'mineral-poor' milk treatment (-1.3%). An effect of normal milk supplementation on diastolic blood pressure could not be demonstrated. The results of the present study indicate a small hypotensive effect of milk consumption, which is attributable to its content of essential minerals.

Adult↗