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Journal Article Ppublish 10 citations

PubMed: 38246697 DOI: 10.1111/dom.15456

Intermediate versus morning chronotype has lower vascular insulin sensitivity in adults with obesity.

Diabetes Obes Metab 26(5):1582-1592

Authors: Steven K Malin, Mary-Margaret E Remchak, Emily M Heiston, Daniel J Battillo, Andrew J Gow, Ankit M Shah, Zhenqi Liu

Affiliations

  • Rutgers University, New Brunswick, New Jersey, USA.
  • Division of Endocrinology, Metabolism & Nutrition, Rutgers University, New Brunswick, New Jersey, USA.
  • New Jersey Institute for Food, Nutrition and Health, Rutgers University, New Brunswick, New Jersey, USA.
  • Institute of Translational Medicine and Science, Rutgers University, New Brunswick, New Jersey, USA.
  • Virginia Commonwealth University, Richmond, Virginia, USA.
  • Division of Endocrinology and Metabolism, Department of Medicifne, University of Virginia Health System, Charlottesville, Virginia, USA.

Abstract

AIM

Chronotype reflects a circadian rhythmicity that regulates endothelial function. While the morning chronotype (MORN) usually has low cardiovascular disease risk, no study has examined insulin action on endothelial function between chronotypes. We hypothesized intermediate chronotypes (INT) would have lower vascular insulin sensitivity than morning chronotype (MORN).

MATERIALS AND METHODS

Adults with obesity were classified per Morningness-Eveningness Questionnaire (MEQ) as either MORN (n = 27, 22 female, MEQ = 63.7 ± 4.7, 53.8 ± 6.7 years, 35.3 ± 4.9 kg/m) or INT (n = 29, 23 female, MEQ = 48.8 ± 6.7, 56.6 ± 9.0 years, 35.7 ± 6.1 kg/m). A 120 min euglycaemic-hyperinsulinaemic clamp (40 mU/m/min, 90 mg/dl) was conducted to assess macrovascular insulin sensitivity via brachial artery flow-mediated dilation (%FMD; conduit artery), post-ischaemic flow velocity (resistance arteriole), as well as microvascular insulin sensitivity via contrast-enhanced ultrasound [e.g. microvascular blood volume (perfusion)]. Fasting plasma arginine and citrulline, as well as fasting and clamp-derived plasma endothelin-1 and nitrate/nitrite, were assessed as surrogates of vasoconstriction and nitric oxide-mediated vasodilation. Aerobic fitness (VOmax) and body composition (dual-energy X-ray absorptiometry) were also collected.

RESULTS

MORN had a higher VOmax compared with INT (p < .01), although there was no difference in fat mass. While fasting FMD was similar between groups, insulin lowered FMD corrected to shear stress and microvascular blood volume in INT compared with MORN after co-varying for VOmax (both p ≤ .02). INT also had a lower fasting nitrate (p = .03) and arginine (p = .07). Higher MEQ correlated with elevated FMD (r = 0.33, p = .03) and lower post-ischaemic flow velocity (r = -0.33, p = .03) as well as shear rate (r = -0.36, p = .02) at 120 min.

CONCLUSION

When measured during the morning, INT had a lower vascular insulin sensitivity than MORN. Additional work is needed to understand endothelial function differences among chronotypes to optimize cardiovascular disease risk reduction.

MeSH

Fasting, Microcirculation, Insulin Resistance, Insulin, Blood, Arginine, Cardiovascular Diseases, Arteries, Blood Volume, Obesity, Nitrates, Plasma, Diabetes Mellitus, Type 2

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