Bariatric surgery as a model to explore the basis and consequences of the Reaven hypothesis: Small, dense low-density lipoprotein and interleukin-6

Diab Vasc Dis Res. 2019 Mar;16(2):144-152. doi: 10.1177/1479164119826479.

Abstract

Background: Reaven originally described the clustering of insulin resistance/hyperinsulinaemia, obesity (particularly visceral), altered cytokine levels, glucose intolerance, hypertriglyceridaemia and low high-density lipoprotein cholesterol. Subsequently, a potentially highly atherogenic small, dense low-density lipoprotein was also reported. We have studied the effect of bariatric surgery on this and other risk factors for atherosclerosis.

Methods: Forty patients (20 with type 2 diabetes mellitus) undergoing bariatric surgery were studied before and 1 year after bariatric surgery.

Results: Twelve months after bariatric surgery, median body mass index had decreased from 49.5 to 36.5 kg/m2, fasting insulin from 21.3 to 7.8 mU/L and insulin resistance (homeostatic model assessment of insulin resistance) from 5.9 to 1.8 (all p < 0.001). Thirteen out of 20 patients had remission from type 2 diabetes mellitus. Highly sensitive C-reactive protein, interleukin-6, fasting triglycerides ( p < 0.001) and small, dense low-density lipoprotein ( p < 0.001) decreased, while high-density lipoprotein cholesterol increased ( p < 0.001) significantly, irrespective of having type 2 diabetes mellitus and/or being treated with statin therapy before surgery.

Conclusion: The association between marked weight loss and change in insulin resistance and hyperinsulinaemia with the change in small, dense low-density lipoprotein and interleukin-6 warrants further investigation. Bariatric surgery provides a model for investigating the mechanisms linking insulin resistance/hyperinsulinaemia to atherosclerosis.

Keywords: Insulin resistance; Reaven’s hypothesis; bariatric surgery; metabolic syndrome; obesity; triglycerides.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Biomarkers / blood
  • Blood Glucose / metabolism
  • Body Mass Index
  • C-Reactive Protein / metabolism
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / diagnosis
  • Diabetes Mellitus, Type 2 / physiopathology
  • Female
  • Gastric Bypass / methods*
  • Humans
  • Insulin / blood
  • Insulin Resistance*
  • Interleukin-6 / blood*
  • Laparoscopy*
  • Lipoproteins, LDL / blood*
  • Male
  • Middle Aged
  • Models, Biological*
  • Obesity / blood
  • Obesity / diagnosis
  • Obesity / physiopathology
  • Obesity / surgery*
  • Particle Size
  • Prospective Studies
  • Time Factors
  • Treatment Outcome
  • Weight Loss*

Substances

  • Biomarkers
  • Blood Glucose
  • IL6 protein, human
  • Insulin
  • Interleukin-6
  • Lipoproteins, LDL
  • C-Reactive Protein