Serum monoterpene levels, glucose homeostasis, lipid profiles, and metabolic syndrome in adults: NHANES, 2013–2014

Abstract

Monoterpenes are organic compounds which have been studied for their medicinal benefits. However, the association between monoterpene exposure and metabolic parameters in humans is unknown. We investigated the connection between three specific monoterpenes (α-pinene, β-pinene, and limonene), glucose homeostasis biomarkers, lipid profiles, and metabolic syndrome (MS) in 1627 adults from the National Health and Nutrition Examination Survey (NHANES) 2013–2014. We found serum levels of α-pinene and β-pinene were positively associated with fasting glucose, total cholesterol, triglyceride, and apolipoprotein B. In addition, increased levels of limonene and Σmonoterpene (sum of three monoterpene chemicals) were linked to higher insulin, β-cell function, total cholesterol, low density lipoprotein cholesterol (LDL-C), triglycerides, and apolipoprotein B. Participants with all three monoterpenes above the 50th percentile had notably higher values for total cholesterol and triglycerides compared to those with all three monoterpenes below the 50th percentile (P for trend <0.001). Regarding MS, higher serum concentrations of α-pinene were linked to an increased risk of high-density lipoprotein cholesterol (HDL-C) insufficiency and hypertriglyceridemia. Elevated concentrations of β-pinene were associated with a higher prevalence of hypertriglyceridemia. Moreover, increased levels of limonene and Σmonoterpene were connected to a higher risk of MS, larger waist circumference, low HDL-C, hypertriglyceridemia, and higher blood pressure according to MS criteria. In conclusion, serum monoterpenes levels were linked to glucose regulation, lipid profiles, and indicators of MS. Further studies are necessary to clarify the potential causal relationships.