Dietary counselling with the Dietary Approaches to Stop Hypertension (DASH) diet for Chinese patients with grade 1 hypertension: a parallel-group, randomised controlled trial

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• 作者：Prof Martin C S Wong ; MD<sup>asup> ; Mandy W M Kwan ; MSc<sup>asup> ; Prof Harry H X Wang ; PhD<sup>bsup><sup> ; sup><sup>csup><sup> ; sup><sup>haoxiangwang@163.com" class="auth_mail" title="E-mail the corresponding authorsup><sup> ; sup><sup>Haoxiang.Wang@glasgow.ac.uk" class="auth_mail" title="E-mail the corresponding authorsup> ; Brian C Y Fong ; MPH<sup>asup> ; Wai Man Chan ; MSc<sup>asup> ; De X Zhang ; PhD<sup>asup> ; Shannon T S Li ; MSc<sup>asup> ; Queenie K Y Lee ; MSc<sup>asup> ; Bryan P Yan ; FRACP<sup>dsup> ; Andrew J S Coats ; FRACP<sup>dsup><sup> ; sup><sup>esup><sup> ; sup><sup>fsup> ; Sian M Griffiths ; FFRH<sup>asup>
• 刊名：The Lancet
• 出版年：2015
• 出版时间：October 2015
• 年：2015
• 卷：386
• 期：supp_S1
• 页码：S8
• 全文大小：55 K

文摘

The Dietary Approaches to Stop Hypertension (DASH) diet has been found to effectively lower blood pressure in Western populations within controlled experimental settings, with an efficacy similar to that of antihypertensive drugs. Nevertheless, studies of the pragmatic effectiveness of DASH counselling in the Chinese population are scarce. The aim of this study was to test the a priori hypotheses that DASH dietary intervention by a single counselling session with a dietician in addition to standard care by physicians improved estimated 10-year cardiovascular risk to a greater extent than standard care given by physicians alone. We also assessed participants who were less likely to have their cardiovascular risk optimised.

sSec_2">Methods

spara20">This parallel-group, randomised controlled trial was done with enrolment at two General Outpatient Clinics and at community health seminars through a primary-care network in Hong Kong. Computer-generated numbers with a block size of six and an allocation ratio of 1:1 were used for group allocation. The research nurse opened the opaque envelope in which the randomised sequence was sealed. Patients were notified into either intervention or control group, whereas the outcome assessors were masked. We recruited male and female patients (aged 40&ndash;70 years) who were newly diagnosed with grade 1 hypertension. Standard care was offered by the attending physician that lasted for 3&ndash;5 minutes, resembling the routine clinic practice. Only patients in the intervention group received a further 25 min one-off dietary counselling, based on the DASH recipe tailored-made for Chinese patients with hypertension, offered by a registered dietitian. Individualised DASH diet goals were recommended and educational pamphlets on the DASH diet were given. 10-year cardiovascular risk was estimated by a recalibrated and validated Chinese version of the Framingham equation. Analysis of covariance was performed to compare between-group differences, with adjustment for the effects of other factors and baseline outcome measures. This trial is registered with the Chinese Clinical Trial Register, number ChiCTRTRC-13003014. The study was approved by the Joint CUHK-NTEC Clinical Research Ethics Committee, Hong Kong. Each trial participant provided written informed consent.

sSec_3">Findings

spara30">We recruited a total of 556 patients (273 males; 283 females) aged 40&ndash;70 years who were newly diagnosed with grade 1 hypertension. 275 patients were randomly assigned to receive standard care and 281 patients were assigned to receive standard care plus DASH-based dietary counselling. Outcome data were available for 504 (91%) patients at 6 months and 485 (87%) patients at 12 months. Between-group analyses showed no difference in the reduction of cardiovascular risk between the two groups at 6 months (&ndash;0·13% [95% CI &ndash;0·50% to 0·23%], p=0·477) and 12 months (&ndash;0·08% [&ndash;0·33% to 0·18%], p=0·568). Multivariate regression analyses showed that men (p=0·012), patients younger than 55 years (p=0·049), current smokers (p=0·007), patients with educational level of junior secondary or below (p=0·009), and those who dined out for main meals for four times or more in a typical week (p=0·038) were significantly associated with no improvement in cardiovascular risk.

sSec_4">Interpretation

spara40">We found that additional counselling with a dietitian for Chinese patients with grade 1 hypertension might not confer additional benefits to those achieved with standard care. This finding does not support routine referral of these patients to dietary counselling. Patients with risk factors identified in this study should receive more clinical attention and regular follow-up to reduce cardiovascular risk. Future research is still necessary to assess the effectiveness of other plausible DASH diet delivery models.

sSec_5">Funding

spara50">The Health and Medical Research Fund and the Food and Health Bureau of the Hong Kong Government.