Effects of a multi-modal resistance exercise program and calcium-vitamin D3 fortified milk on blood pressure and blood lipids in middle-aged and older men: secondary analysis of an 18-month factorial design randomised controlled trial.

Abstract

Physical activity and dietary interventions are recommended as front-line therapy for prevention and management of cardiovascular disease. This study investigated the independent and combined effects of low-fat, calcium-vitamin D3 fortified milk and multi-modal exercise training on blood pressure (BP) and blood lipids in middle-aged and older men. This was a pre-planned secondary analysis of an 18-month, randomised controlled trial. Community-dwelling men aged 50-79years (n = 180) were randomised into (i) exercise + fortified milk; (ii) fortified milk; (iii) exercise; or (iv) control. The low-fat milk (400mL/day) was fortified with 1,000mg/day calcium and 800IU/day of vitamin-D3, whilst the exercise intervention consisted of three sessions/week of resistance- and weight-bearing impact exercises. Resting BP and fasting lipids were assessed at baseline, 6 (lipids only), 12 and 18months. Mean ± SD serum 25(OH)D and calcium intake for the entire cohort at baseline was 86 ± 36nmol/L and 1002 ± 397mg/day, respectively, with 10% classified as vitamin-D insufficient and 58% reportinga calcium intake below 1000mg/day. There were no exercise-by-fortified milk interactions, nor any main-group effects for exercise or milk on BP or lipids at any time. However, there were significant reductions from baseline to 18months in systolic (mean change, 5-8mmHg) and diastolic (4-6mmHg) BP in the exercise, fortified milk and control groups. All results remained largely unchanged after adjusting for use of anti-hypertensive or lipid lowering medication, weight or fat mass, or only including men with hypertension (n = 89) or dyslipidemia (n = 130) at baseline. Supplementation with low-fat, calcium + vitamin D3 fortified milk and a multi-modal exercise program, alone or in combination, was not effective for improving BP or blood lipids in community-dwelling middle-aged and older men.