The role of lipids as risk factors for cardiovascular events is well-documented, although events studied have largely been broad classes without specific detail. This study will examine a more refined set of endpoints.

The role of lipids (cholesterol and triglycerides) as risk factors for cardiovascular events is well-documented. The Emerging Risk Factors Collaboration found approximately log-linear adjusted associations of cholesterol concentrations with risks of first-time non-fatal myocardial infarction; coronary heart disease (CHD) death; ischaemic, haemorrhagic and unclassified stroke. They also found that triglycerides concentration was not independently related with CHD risk after controlling for HDL cholesterol (HDL-C), non-HDL-C, and other standard risk factors. The Prospective Studies Collaboration found that Higher HDL-C and lower non-HDL-C levels were approximately independently associated with lower ischaemic heart disease mortality. By focusing on broad outcomes these large meta-analyses conflate the association between development of the different cardiovascular disease (CVD) phenotypes, disease progression and mortality from cardiovascular causes.

With linked electronic health records, we have the potential for a cohort with sufficient size and clinical detail to investigate the association between lipid concentrations and initial presentation of a range of CVD phenotypes across cerebral, coronary, abdominal and peripheral arterial circulations.

Inclusion Criteria:

• Aged 30 to 100, had at least one year of electronic health record data which meet General Practice Research Database data quality standards

Exclusion Criteria:

• No record indicating any cardiovascular disease phenotypes

The cohort used in the present analysis was drawn from patients registered with 225 GPRD general practices in England which consented to data linkage, covering approximately 5% of the UK population. We used an open cohort design, where participants joined the cohort when they met the inclusion criteria at any point between 1st January 2001 and 25th March 2010, the date of the last GPRD data submission. Patients were included in cohort if, prior to study entry, they were aged 30 to 100, had at least one year of electronic health record data which meet General Practice Research Database data quality standards, and had no record indicating any cardiovascular disease phenotypes. Patients were followed up until the date of an initial presentation of one of our cardiovascular endpoints or were censored on the date of leaving the practice or the date of last data submission from their practice.