The role of melatonin receptor 1B gene (MTNR1B) in the susceptibility to depression and type 2 diabetes comorbidity

Elevated remnant cholesterol and the risk of prevalent major depressive disorder: a nationwide population-based study

Background

Remnant cholesterol (RC) has received increasing attention due to its association with a variety of diseases. However, comprehensive population-based studies elucidating the relationship between RC and major depressive disorder (MDD) are limited. The current study aimed to determine the association between RC and MDD in US adults.

Methods

Cross-sectional data of US adults with complete RC and depression information were obtained from the National Health and Nutrition Examination Survey (NHANES) 2005-2018. MDD was evaluated using the Patient Health Questionnaire (PHQ-9). Multivariate logistic regression, sensitivity analysis, and spline smoothing plot method were conducted to explore the relationship between RC and depression. The cut-off point was calculated using recursive partitioning analysis when segmenting effects emerged. The area under the receiver operating characteristic (ROC) curve (AUC), calibration curve, Hosmer-Lemeshow test, the decision curve analysis (DCA), and clinical impact curve (CIC) were employed to evaluate the performance of RC in identifying MDD. Subgroup analyses and interaction tests were performed to explore whether the association was stable in different populations.

Results

A total of 9,173 participants were enrolled and participants in the higher RC quartile tended to have a higher PHQ-9 score and prevalence of MDD. In the fully adjusted model, a positive association between RC and PHQ-9 score and MDD was both observed (β=0.54, 95% CI 0.26~0.82; OR=1.43, 95% CI 1.15~1.78). Participants in the highest RC quartile had a 0.42-unit higher PHQ-9 score (β=0.42, 95% CI 0.15~0.69) and a significantly 32% higher risk of MDD than those in the lowest RC quartile (OR=1.32, 95% CI 1.05~1.66). Spline smoothing plot analysis further confirmed the positive and non-linear association between RC and PHQ-9 and MDD. ROC analysis (AUC=0.762), the Hosmer-Lemeshow test (χ2 = 6.258, P=0.618), and calibration curve all indicated a high performance and goodness-of-fit of the multivariate model. DCA and CIC analysis similarly demonstrated a positive overall net benefit and clinical impact for the model. Subgroup analyses and interaction tests suggested that the relationship between RC and depression remained stable across subgroups and was unaffected by other factors other than diabetes, hypertension, or hyperlipidemia.

Conclusion

An elevated RC is associated with a higher risk of prevalent MDD among US adults, especially in those with diabetes, hypertension, or hyperlipidemia. The present results suggested that the management of RC levels and comorbidities may contribute to alleviating the occurrence of MDD.

The melatonin receptor genes are linked and associated with the risk of polycystic ovary syndrome

Polycystic ovarian syndrome (PCOS) is a genetically complex disorder that involves the interplay of multiple genes and environmental factors. It is characterized by anovulation and irregular menses and is associated with type 2 diabetes. Neuroendocrine pathways and ovarian and adrenal dysfunctions are possibly implicated in the disorder pathogenesis. The melatonin system plays a role in PCOS. Melatonin receptors are expressed on the surface of ovarian granulosa cells, and variations in the melatonin receptor genes have been associated with increased risk of PCOS in both familial and sporadic cases. We have recently reported the association of variants in MTNR1A and MTNR1B genes with familial type 2 diabetes. In this study, we aimed to investigate whether MTNR1A and MTNR1B contribute to PCOS risk in peninsular families. In 212 Italian families phenotyped for PCOS, we amplified by microarray 14 variants in the MTNR1A gene and 6 variants in the MTNR1B gene and tested them for linkage and linkage disequilibrium with PCOS. We detected 4 variants in the MTNR1A gene and 2 variants in the MTNR1B gene significantly linked and/or in linkage disequilibrium with the risk of PCOS (P < 0.05). All variants are novel and have not been reported before with PCOS or any of its related phenotypes, except for 3 variants previously reported by us to confer risk for type 2 diabetes and 1 variant for type 2 diabetes-depression comorbidity. These findings implicate novel melatonin receptor genes' variants in the risk of PCOS with potential functional roles.