Objective: To assess effects of multifactorial lifestyle modification on antihypertensive drug needs in treated hypertensive individuals.

Design: Randomized controlled trial.

Setting: Research studies unit.

Participants: Overweight hypertensive patients, receiving one or two antihypertensive drugs, were recruited by advertising, and allocated randomly to a usual care group (controls; n = 118) or a lifestyle modification group (programme group; n = 123).

Intervention: A 4-month programme of weight loss, a low-sodium 'Dietary Approaches to Stop Hypertension'-type diet with added fish, physical activity and moderation of alcohol intake. After 4 months, if mean 24-h ambulatory blood pressure (ABP) was less than 135/85 mmHg, antihypertensive drugs were withdrawn over 4 weeks and long-term home blood pressure monitoring was begun.

Main outcome measures: Antihypertensive drug requirements, ABP, weight, waist girth at 4 months and 1-year follow-up.

Results: Ninety control group and 102 programme group participants completed the study. Mean 24-h ABP changed after 4 months by -1.0/-0.3 +/- 0.5/0.4 mmHg in controls and -4.1/-2.1 +/- 0.7/0.5 mmHg with the lifestyle programme (P < 0.01). At follow-up, changes in the two groups were not significantly different (4.1/1.3 +/- 1.1/1.0 mmHg in controls; 2.5/-0.1 +/- 1.1/0.8 mmHg in the programme group; P = 0.73). At 4 months, drug withdrawal differed significantly between the groups (P = 0.038) in men (control 44%; programme 66%) but not in women (65 and 64%, respectively; P = 0.964). At follow-up, sex-related differences were not significant, and 41% in the control group and 43% in the programme group maintained drug-withdrawal status. With the programme, net weight loss was 3.3 kg (P < 0.001) at 4 months and 3.0 kg (P < 0.001) at follow-up; respective net decreases in waist girth were 3.3 cm (P < 0.001) and 3.5 cm (P < 0.001).

Conclusions: A 4-month multifactorial lifestyle modification in patients with treated hypertension reduced blood pressure in the short-term. Decreased central obesity persisted 1 year later and could reduce overall cardiovascular risk.