Effects of a Nutrition Education Programme in Stage IV Cardiac Rehabilitation Patients: A 3-Arm Randomised Controlled Trial

Abstract

This trial examined the influence of two nutrition intervention programmes on health-related and nutritional intake indices pertinent to cardiovascular disease compared to usual care in stage IV cardiac rehabilitation patients. Sixty-six patients were recruited from the Heartbeat North-West cardiac rehabilitation centre in Preston (United Kingdom). Patients were randomly assigned to Usual care, Biggest loser or Nutrition education arms. Usual care undertook their usual two exercise classes per week without nutritional support, Biggest loser underwent weekly education sessions focussing on weight loss using the themes within the British Heart Foundation ‘So You Want to Lose Weight for Good’ guidelines, and Nutrition education followed the same themes as Biggest loser but in a more focussed manner informed by patient focus groups. In total, this was a 12-week trial in which patients spent 6 weeks engaged in their allocated intervention arm, after which all participants switched to Usual care. The primary outcome was systolic blood pressure, and secondary measures of anthropometric, blood biomarker, nutritional knowledge (via the Mediterranean Diet Assessment Tool) and nutritional intake indices were measured at baseline, 6 weeks, and 12 weeks (follow-up). Intention-to-treat analyses revealed no significant alterations in the primary outcome (Usual care: baseline = 130.45 mmHg, 6 weeks = 127.83 mmHg, and follow-up = 126.35 mmHg, Biggest loser: baseline = 133.50 mmHg, 6 weeks = 123.06 mmHg, and follow-up = 135.22 mmHg, or Nutrition education: baseline = 135.23 mmHg, 6 weeks = 129.20 mmHg, and follow-up = 126.26 mmHg) between arms. However, at 6 weeks, improvements in triglycerides were significantly greater in Usual care (baseline = 1.61 mmol/L and 6 weeks = 1.43 mmol/L) group compared to Nutrition education (baseline = 1.70 mmol/L and 6 weeks = 2.21 mmol/L). Improvements in nutrition knowledge were significantly greater in Nutrition education (baseline = 8.48, 6 weeks = 9.77, and follow-up = 10.07) compared to Usual care (baseline = 7.71, 6 weeks = 8.00, and follow-up = 8.00) and Biggest loser (baseline = 7.71, 6 weeks = 8.73, and follow-up = 8.36). At 6 weeks, the Biggest loser group (baseline = 4.75 g and 6 weeks = 3.83 g) exhibited significantly greater improvements in salt intake compared to Usual care (baseline = 4.87 g and 6 weeks = 4.28 g) and Nutrition education (baseline = 19.25 g and 6 weeks = 16.78 g) in saturated fatty acids compared to Usual care (baseline = 20.26 g and 6 weeks = 21.34 g). This trial shows the effectiveness of nutritional interventions for improving nutritional knowledge and dietary practices in stage IV cardiac rehabilitation, but the mechanisms and longer-term effects of increased triglyceride levels in the Nutrition education group requires further exploration.