A study on the impact of cholesterol-lowering medication has highlighted an issue with a new class of drugs that could impair lung function in some patients.

The University of South Australia study, published in the British Journal of Clinical Pharmacology, compares cholesterol-lowering medications (LDL-C drugs) to a range of clinical and heart and brain MRI biomarkers.

Genetic data from 340,000 UK Biobank participants was analyzed to explore the risks and benefits of LDL-C drugs. The outcomes have been, in the vast number of cases, that medication prescribed for high cholesterol does what it promises: significantly lowers the risk of cardiovascular disease, high blood pressure, diabetes, and age-related diseases. It does not cause any other adverse health conditions except diarrhea in some people.

However, lipid-lowering medications that clear cholesterol from the cells—known as PCSK9 inhibitors—could impair lung function. Further studies are needed on their long-term side effects, researchers say.

Genetic variants reflecting another cholesterol-lowering medication, statins, were found to correlate with higher BMI and body fat, as well as reduced testosterone. Statins are the most common cholesterol-lowering medication prescribed.

One unexpected benefit of taking statins was found, with some people seeing an increase in brain volume of the hippocampus, which may reduce the risk of dementia and depression.

University of South Australia PhD student Kitty Pham, lead author of the paper, says the findings highlight the importance of delving deeper to understand potential long-term effects of different medications.

“Our study reveals associations with lung function and brain size, which may influence how these drugs are prescribed or repurposed in the future,” says Pham in a release. “These findings help us to understand how people may react to different drugs and assess the viability of new drug pathways.”

Compared to statins, which inhibit the production of cholesterol, PCSK9 drugs destroy cholesterol in the cells. The latter are a newer class of drug, so less is known about their long-term safety.

Chief investigator professor Elina Hypponen, center director of the Australian Centre for Precision Health at University of South Australia, says genetic information was used to compare the outcomes of a range of LDL-C lowering drugs, working in different ways.

“This normally would not be practical in a clinical trial or for such a large sample size, but genetic analyses such as the one we have conducted can really help with drug safety profiling by uncovering links with diseases and biomarkers,” says Hypponen in a release.