Lifestyle trajectories and ischaemic heart diseases: a prospective cohort study in UK Biobank.

It is known that an unhealthy lifestyle at baseline was associated with an increased risk of cardiovascular diseases (CVDs), but the risk attributed to the lifestyle changes (or trajectories) over the long term has not been well quantified. Meanwhile, the effects of lifestyle, either in baseline level or trajectories, on different CVD subtypes such as ischaemic heart diseases (IHDs) and stroke varied. Thus, this study used the data from UK Biobank to construct a weighted unhealthy lifestyle score and to evaluate the prospective associations of baseline and long-term trajectories of the unhealthy lifestyle score with the risk of incident IHD. A total of 352 251 and 29 164 participants were included in the unhealthy lifestyle construction and lifestyle trajectory analysis, respectively. We found a poorer lifestyle at baseline was significantly associated with an increased risk of incident IHD in a linear dose­response fashion. Besides, a declined lifestyle trajectory was associated with an increased risk of incident IHD, irrespective of baseline lifestyle levels, and such an association was stronger among individuals with hypertension, diabetes, or hyperlipidaemia. Compared with the maintainers, risks of incident IHD attenuated when individuals improved their lifestyle and strengthened when declined their lifestyle.A declined lifestyle trajectory increased the risk of incident IHD, irrespective of baseline lifestyle levels. Such association was stronger among participants with hypertension, diabetes, or hyperlipidaemia.Compared with the maintainers of lifestyle, risks of incident IHD attenuated when individuals improved their lifestyle and strengthened when declined their lifestyle.