It is generally agreed that high levels of low-density lipoprotein cholesterol (LDL-C, which is regarded as a bad blood lipid) and triglyceride (TG), but low levels of high-density lipoprotein cholesterol (HDL-C, which is regarded as a good blood lipid), can lead to cardiovascular disease. However, some studies suggested that low LDL-C, and perhaps high HDL-C and high TG, might increase the risks of other diseases, such as, some eye diseases, Alzheimer’s disease, Parkinson’s disease, diabetes, cirrhosis, some respiratory and autoimmune diseases. However, limitations of existing evidence make it difficult to draw any conclusion. This study aims to investigate whether or not low LDL-C, high HDL-C and high TG, levels are associated with increased risks of these diseases and all-cause deaths. Use of the data from a very large number of people in England will provide comprehensive information with a wide range of cholesterol levels and variety of clinical outcomes during over 20 years of follow-up. Our study will include those who have a baseline blood lipids measurement while free of these specified diseases. We will employ statistical methods to examine whether blood lipids levels are related to the first diagnosis of these diseases. The finding of the study will provide new insight into the role of blood lipids across the whole range of values.
Observational studies have shown that LDL-C, HDL-C, and TG levels might be associated with some autoimmune disorders and some idiosyncratic adverse events. Due to limitations of existing evidence, however, the role of blood lipids in non-cardiovascular diseases is still questioned. This observational study aims to examine the associations between LDL-C, HDL-C, TG, and the incidence of all-cause mortality, and of diverse non-cardiovascular diseases, including cataract, age-related macular degeneration, Alzheimer’s disease, Parkinson’s disease, type 2 diabetes, cirrhosis, psoriasis, rheumatoid arthritis, multiple sclerosis, systemic sclerosis, chronic obstructive pulmonary disease, and idiopathic pulmonary fibrosis. Use of linked-data from hospital and GP records will allow us to investigate the full spectrum of blood lipids levels. We will include the population without pre-existing disease of interest whose blood lipids measurement was available during 1998 to 2018, and we will follow them up until the first presentation of disease of interest, death, or transfer out of the practice, whichever occurred first. Hazard ratios of the incidence of disease for each unit change in blood lipids will be calculated using time-dependent Cox proportional hazard models adjusted for potential confounders. We will also examine the role of age, gender as effect modifiers. The findings of this study will allow the investigator to conduct further research to understand more about the role of blood lipids in non-cardiovascular diseases.
Incidence of all-cause and cause-specific mortality and 12 non-cardiovascular diseases as follows: cataract, age-related macular degeneration (AMD), Alzheimer’s disease, Parkinson’s disease, type 2 diabetes, cirrhosis, psoriasis, rheumatoid arthritis, multiple sclerosis, systemic sclerosis, chronic obstructive pulmonary disease, and idiopathic pulmonary fibrosis.
Harry Hemingway - Chief Investigator - University College London ( UCL )
Nat Na-Ek - Corresponding Applicant - Farr Institute of Health Informatics Research
Amitava Banerjee - Collaborator - University College London ( UCL )
Arturo Gonzalez-Izquierdo - Collaborator - University College London ( UCL )
Spiros Denaxas - Collaborator - University College London ( UCL )
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation