Bone health and risk factors of cardiovascular disease--a cross-sectional study in healthy young adults.

OBJECTIVE: Both osteoporosis and cardiovascular disease (CVD) are diseases that comprise a growing medical and economic burden in ageing populations. They share many risk factors, including ageing, low physical activity, and possibly overweight. We aimed to study associations between individual risk factors for CVD and bone mineral density (BMD) and turnover markers (BTMs) in apparently healthy cohort. DESIGN: A cross-sectional assessment of 155 healthy 32-year-old adults (74 males) was performed for skeletal status, CVD risk factors and lifestyle factors. METHODS: We analysed serum osteocalcin, procollagen I aminoterminal propeptide (P1NP), collagen I carboxy-terminal telopeptide (ICTP) and urine collagen I aminoterminal telopeptide (U-NTX), as well as serum insulin, plasma glucose, triglyceride and HDL-cholesterol levels. BMD, fat and lean mass were assessed using DXA scanning. Associations were tested with partial correlations in crude and adjusted models. Bone status was compared between men with or without metabolic syndrome (defined according to the NCEP-ATPIII criteria) with multivariate analysis. RESULTS: Osteocalcin and P1NP correlated inversely with insulin (R = -0.243, P = 0.003 and R = -0.187, P = 0.021) and glucose (R = -0.213, P = 0.009 and R = -0.190, P = 0.019), but after controlling for fat mass and lifestyle factors, the associations attenuated with insulin (R = -0.162, P = 0.053 and R = -0.093, P = 0.266) and with glucose (R = -0.099, P = 0.240 and R = -0.133, P = 0.110), respectively. Whole body BMD associated inversely only with triglycerides in fully adjusted model. In men with metabolic syndrome, whole body BMD, osteocalcin and P1NP were lower compared to healthy men, but these findings disappeared in fully adjusted model. CONCLUSIONS: In young adults, inverse associations between BTM/BMD and risk factors of CVD appeared in crude models, but after adjusting for fat mass, no association continued to be present. In addition to fat mass, lifestyle factors, especially physical activity, modified the associations between CVD and bone characteristics. Prospective studies are needed to specify the role of mediators and lifestyle factors in the prevention of CVD and osteoporosis.

Breast-fed infants and their later cardiovascular health: a prospective study from birth to age 32 years.

The aim of the present study was to evaluate the impact of infant breast-feeding on cardiovascular risk in young adults. This unique study group involved 158 subjects (eighty-two females) originally collected prospectively at birth in 1975 and followed up to the age of 32 years. Frequent visits during the first year guaranteed the knowledge of the precise duration of breast-feeding. All infants received at least some breast milk. Participants were assessed for both individual cardiovascular risk factors (blood pressure, plasma lipids, homeostatic model assessment of insulin resistance and waist circumference) and the general clinical risk of cardiovascular events by calculating the Framingham risk score (FRS) and the metabolic syndrome criteria score (NCEP-ATPIII; National Cholesterol Education Program's Adult Treatment Panel III). Data on lifestyle factors were carefully collected. Linear regression analyses revealed that the effect of the duration of breast-feeding was not relevant (0·02 decrease in the FRS per one additional breast-feeding month; 95 % CI - 0·19, 0·09). Similarly, the effect of breast-feeding was minor on all of the individual cardiovascular risk factors. We used sex, physical activity, dietary fat and vitamin C, smoking and alcohol consumption as covariates. Again, logistic regression analyses detected no significant impact of the duration of breast-feeding on the risk of the metabolic syndrome according to the NCEP-ATPIII (OR 0·95, 95 % CI 0·8, 1·1). The strongest independent predictor for later CVD risk was male sex. In conclusion, in this prospectively followed cohort of young adults born at term and at weight appropriate for gestational age, the duration of breast-feeding did not have an impact on the accumulation of cardiovascular risk factors.

Breastfeeding and determinants of adult body composition: a prospective study from birth to young adulthood.

BACKGROUND: The impact of breastfeeding on adult body composition is controversial. We evaluated effects of lifestyle and childhood-related factors, including infant feeding, on adult body composition. METHODS: We determined total body and trunk fat and lean mass by densitometry in 158 adults who were born full-term and prospectively followed from birth to the age of 32 years. Data on various factors, extending from infancy to adulthood, with potential effect on body composition, were recorded. RESULTS: Scapular skinfold thickness at 12 months correlated with adult trunk (R = 0.22, p = 0.005) and body fat percentage (R = 0.18, p = 0.023). In linear regression analysis, current physical activity (R = -0.33, p < 0.001) and maternal BMI (R = 0.28, p = 0.002) were associated with adult body fat percentage. Gender (R = 0.78, p < 0.001) and weight gain during infancy (R = 0.147, p = 0.008) were associated with adult lean mass. In the analysis of covariance, prolonged breastfeeding tended to lead to lower fat percentage in adulthood, but no direct association with the duration of breastfeeding and adult body composition was confirmed. CONCLUSIONS: Current physical activity, growth in infancy, gender and maternal BMI influence adult body composition. Breastfeeding has an indirect influence on adult body fat accumulation by affecting growth and body adiposity in infancy.

Infant milk feeding influences adult bone health: a prospective study from birth to 32 years.

BACKGROUND: Peak bone mass, attained by early adulthood, is influenced by genetic and life-style factors. Early infant feeding and duration of breastfeeding in particular, associate with several health-related parameters in childhood. The aim of this study was to examine whether the effects of early infant feeding extend to peak bone mass and other bone health characteristics at adult age. METHODS AND FINDINGS: A cohort of 158 adults (76 males) born in Helsinki, Finland, 1975, prospectively followed up from birth, underwent physical examination and bone densitometry to study bone area, bone mineral content (BMC), and bone mineral density (BMD) at 32 years of age. Life-style factors relevant for bone health were recorded. For data analysis the cohort was divided into three equal-size groups according to the total duration of breastfeeding (BF): Short (≤3 months), Intermediate and Prolonged (≥7 months) BF groups. In males short BF is associated with higher bone area, BMC, and BMD compared to longer BF. Males in the Short BF group had on average 4.7% higher whole body BMD than males in the Prolonged BF group. In multivariate analysis, after controlling for multiple confounding factors, the influence of BF duration on adult bone characteristics persisted in males. Differences between the three feeding groups were observed in lumbar spine bone area and BMC, and whole body BMD (MANCOVA; p = 0.025, p = 0.013, and p = 0.048, respectively), favoring the Short BF group. In women no differences were observed. CONCLUSIONS: In men, early infant milk feeding may have a significant impact on adult bone health. A potential explanation is that the calcium and phosphate contents were strikingly higher in formula milk and commercial cow milk/cow milk dilutions as opposed to human milk. Our novel finding merits further studies to determine means to ensure optimal bone mass development in infants with prolonged breastfeeding.