The association of a priori and a posterior dietary patterns with the risk of incident stroke in Chinese older people in Hong Kong

Background: Dietary patterns can be identified by a priori and a posterior approaches. Limited data have related dietary patterns with stroke risk in Chinese population. This study examined stroke risk associated with patterns identified by both approaches. Data on 1,338 Chinese men and 1,397 Chinese women aged >= 65 years participating in a cohort study examining the risk factors for osteoporosis in Hong Kong were analyzed. Baseline dietary data were collected between 2001 and 2003 using a validated food frequency questionnaire. Adherence to a priori dietary patterns including the Mediterranean Diet Score (MDS) and the Dietary Approaches to Stop Hypertension (DASH) was assessed. Factor analysis (FA) identified three a posterior dietary patterns: "vegetables-fruits", "snacks-drinks-milk products", and "meat-fish". Data on incidence of stroke were retrieved from an official database in 2008. Cox regression was used to estimate hazard ratios (HRs) for stroke risk adjusted for potential confounders. There were 156 incident stroke events during a median follow up of 5.7 years. A posterior dietary patterns derived by FA were not associated with risk of incident stroke in either men or women. MDS was inversely associated with risk of incident stroke [Adjusted HR=0.55 (95% CI: 0.31-0.99) of the highest level of MDS compared with the lowest level, ptrend=0.008] in men but not in women. Similar non-significant inverse association was observed between DASH accordance and stroke risk in men [Multivariate HR (95% CI) of the DASH score of >=4.5 = 0.62 (0.38-1.04) compared with the DASH score of <=4, ptrend = 0.068] but not in women. Our findings suggest that higher MDS and possibly higher DASH scores were associated with lower stroke risk in Chinese older people in Hong Kong.