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Bariatric surgery may decrease PCSK9 levels in severe obesity

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August 29, 2017

Benoit Arsenault
Benoit Arsenault

Circulating levels of PCSK9 and LDL cholesterol may decline following biliopancreatic diversion with duodenal switch in adults with severe obesity, according to study findings.

Benoit Arsenault, PhD, of the faculty of medicine at Laval University in Quebec, and colleagues evaluated data on 20 men and 49 women (mean age, 41.5 years) with severe obesity before and 24 hours, 5 days, 6 months and 12 months after undergoing biliopancreatic diversion with duodenal switch and controls at baseline and 6 and 12 months. Researchers sought to determine the acute and chronic impact of the surgery on PCSK9 levels and whether the acute impact could be explained by surgery-related calorie restriction.

One day after surgery, PCSK9 levels had increased 13.4% from baseline but then returned to baseline levels on day 5. At 12 months, PCSK9 levels were 9.5% lower than baseline (P < .0001). From baseline to 1 day after surgery, LDL cholesterol levels decreased by 36.2% (P < .0001) and were 30% lower than baseline at 12 months (P < .0001).

Among 23 participants on statins at baseline, all discontinued the medication after surgery.

PCSK9 levels were negatively associated with body weight and fat mass and were positively associated with glucose levels and HbA1c. Changes in insulin levels were positively associated with 6-month changes in PCSK9 levels, whereas homeostasis model of assessment for insulin resistance and 12-month changes in PCSK9 were positively associated with changes in HDL cholesterol, adiponectin levels and HbA1c.

Eight participants with type 2 diabetes and severe obesity who were eligible for surgery were selected for a 3-day caloric restriction protocol. Researchers measured PCSK9 levels during the restriction and 2 months before and after the surgery. PCSK9 levels were lower 2 days following initiation of caloric restriction compared with baseline.

According to the researchers, further study is needed to improve understanding of the mechanisms underlying the effects of surgery on PCSK9 levels, as well as the clinical

“We know that PCSK9 levels are associated with the risk of cardiovascular disease and that targeting PCSK9 with antibodies decreases CV outcomes in patients at high risk for heart disease,” Arsenault told Endocrine Today. “However, little is known about what influences circulating PCSK9 levels. Our results extend previous findings showing that individuals with excess body weight had higher circulating PCSK9 levels by showing that bariatric surgery decreases PCSK9 levels. This finding could explain to a certain extent why LDL cholesterol decreases after bariatric surgery."

According to the researchers, further study is needed to improve understanding of the mechanisms underlying the effects of surgery on PCSK9 levels, as well as the clinical impact of surgery on PCSK9 in relation to cardiovascular disease risk. – by Amber Cox

For more information:

Benoit Arsenault, PhD, can be reached at benoit.arsenault@criucpq.ulaval.ca.

Disclosures: Arsenault reports receiving research funding from Pfizer for scientific work on PCSK9. Please see the full study for a list of all other authors’ relevant financial disclosures.