Effectiveness of a dietary intervention strategy in general practice: effects on blood lipids, health and well-being

OBJECTIVES: To evaluate the effect of a dietary treatment programme on blood cholesterol concentration in hypercholesterolaemic patients in general practice and to analyse subjectively experienced side-effects.

DESIGN: A 1-year parallel trial comparing a new treatment programme with conventional treatment.

SETTING: General practitioners in Roskilde county, Denmark.

SUBJECTS: 355 men and women, aged 20-60 years, with a persistent blood cholesterol concentration above age- and gender-specific cut-off points (265 in an intervention group and 90 in a control group).

INTERVENTION: A treatment strategy based on collaboration between doctor and dietitian using individual dietary advice and feedback from measured biological parameters.

MAIN OUTCOME MEASURES: Serum lipids, body weight, blood pressure, dietary behaviour, health parameters, quality of life parameters and acceptance by patients and general practitioners.

RESULTS: Total blood cholesterol concentration decreased by 14% (1.07 mmol l(-1), P < 0.0001) in 159 patients in the intervention group, not having any lipid altering drug during treatment, in addition to 3% from screening to start of treatment. In 65 patients in the control group, without any lipid altering drug, the reduction of cholesterol concentration was 4% (0.27 mmol l(-1), P < 0.01; intervention vs. control P < 0.001). In the intervention group overweight subjects (body mass index > 30) reduced body weight by 6% (P < 0.0001). Systolic blood pressure was reduced by 11% (P < 0.0001) and diastolic blood pressure by 10% (P < 0.0001) and 19% (P < 0.003) for intervals 90-110 mmHg and > 110 mmHg, respectively. Risk score decreased and self-assessed health, physical and psychological well-being improved.

CONCLUSIONS: The treatment strategy tested proved to be efficient, without side-effects and well accepted by patients and general practitioners. The results strongly suggest that hypercholesterolaemia can efficiently be treated non-pharmacologically in general practice.