Milk consumption throughout life and bone mineral content and density in elderly men and women

Association between bone mineral density and bone mineral content in old age and milk consumption in adolescence, midlife, and old age was assessed. The association was strongest for milk consumption in midlife: those drinking milk daily or more often had higher bone mineral density and content in old age than those drinking milk seldom or never.

INTRODUCTION

The role of lifelong milk consumption for bone mineral density (BMD) and bone mineral content (BMC) in old age is not clear. Here we assess the association between hip BMD and BMC in old age and milk consumption in adolescence, midlife, and current old age.

METHODS

Participants of the Age, Gene/Environment Susceptibility-Reykjavik Study, aged 66-96 years (N = 4,797), reported retrospective milk intake during adolescence and midlife as well as in current old age, using a validated food frequency questionnaire. BMC of femoral neck and trochanteric area was measured by volumetric quantitative computed tomography and BMD obtained. Association was assessed using linear regression models. Differences in BMC, bone volume, and BMD in relation to milk intake were portrayed as gender-specific Z-scores.

RESULTS

Men consuming milk ≥ once/day during midlife had 0.21 higher Z-scores for BMD and 0.18 for BMC in femoral neck (95 % confidence interval 0.05-0.39 and 0.01-0.35, respectively) compared with < once/week. Results were comparable for trochanter. For women the results were similar, with slightly lower differences according to midlife milk consumption. For current and adolescent milk consumption, differences in Z-scores were smaller and only reached statistical significance in the case of BMD for current consumption in men, while this association was less pronounced for BMC.

CONCLUSIONS

Our data suggest that regular milk consumption throughout life, from adolescence to old age, is associated with higher BMC and BMD in old age, with no differences seen in bone volume. The strongest associations are seen for midlife milk consumption in both genders.

Persistence of the effect of birth size on dysglycaemia and type 2 diabetes in old age: AGES-Reykjavik Study

We studied the effect of birth size on glucose and insulin metabolism among old non-diabetic individuals. We also explored the combined effect of birth size and midlife body mass index (BMI) on type 2 diabetes in old age. Our study comprised 1,682 Icelanders whose birth records included anthropometrical data. The same individuals had participated in the prospective population-based Reykjavik Study, where BMI was assessed at a mean age of 47 years, and in the AGES-Reykjavik Study during 2002 to 2006, where fasting glucose, insulin and HbA1c were measured and homeostasis model assessment for the degree of insulin resistance (HOMA-IR) calculated at a mean age of 75.5 years. Type 2 diabetes was determined as having a history of diabetes, using glucose-modifying medication or fasting glucose of >7.0 mmol/l. Of the participants, 249 had prevalent type 2 diabetes in old age. Lower birth weight and body length were associated with higher fasting glucose, insulin, HOMA-IR and HbA1c among old non-diabetic individuals. Higher birth weight and ponderal index at birth decreased the risk for type 2 diabetes in old age, odds ratio (OR), 0.61 [95 % confidence interval (CI), 0.48-0.79] and 0.96 (95 % CI, 0.92-1.00), respectively. Compared with those with high birth weight and low BMI in midlife, the odds of diabetes was almost five-fold for individuals with low birth weight and high BMI (OR, 4.93; 95 % CI, 2.14-11.37). Excessive weight gain in adulthood might be particularly detrimental to the health of old individuals with low birth weight.

The presence of total knee or hip replacements due to osteoarthritis enhances the positive association between hand osteoarthritis and atherosclerosis in women: the AGES-Reykjavik study

OBJECTIVE

This study examines the relationship between total knee replacements (TKR), total hip replacements (THR) or replacements of either joint (total joint replacement; TJR) due to osteoarthritis and atherosclerosis in a large population-based study.

METHODS

The participants were 2195 men and 2975 women, mean age 76 ± 6 years. The osteoarthritis data were analysed in relation to measures of atherosclerosis, including carotid artery intima media thickness and plaque severity (ultrasound), coronary and aortic calcifications (CT), cerebral white matter lesions (MRI) and a history of previous cardiac and cerebral events.

RESULTS

The prevalence of TKR was 223 (4.3%) and THR 316 (6.1%). The presence of TJR in women was associated with a non-significant trend towards increased carotid plaque severity, coronary calcifications and periventricular white matter hyperintensities (PVH) but not with a history of cardiac or cerebral events. No associations were seen in men. When TJR were grouped according to the presence or absence of hand osteoarthritis (HOA) there was a highly significant association in the order -TJR/-HOA < +TJR/-HOA < -TJR/+HOA < +TJR/+HOA, for carotid plaque severity, coronary calcifications and PVH.

CONCLUSION

The presence of TJR did not show a significant independent association with atherosclerosis but enhanced the strength of the positive association between HOA and subclinical atherosclerosis in women.