Melatonin Pathway and Atenolol-Related Glucose Dysregulation: Is There a Correlation?

Lower melatonin level, melatonin receptor gene variations, and atenolol treatment are associated with glucose dysregulation. We investigated whether atenolol-related glucose and melatonin changes are correlated, and whether single nucleotide polymorphisms (SNPs) in melatonin candidate genes contribute to interindividual variation in glucose change. Hypertensive Caucasians (n = 232) from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) study treated with atenolol for 9 weeks were studied. Urinary 6-sulfatoxymelatonin (aMT6s) was measured pre- and posttreatment and normalized to urinary creatinine. Pharmacogenetic effects on glucose change of 160 SNPs in 16 melatonin candidate genes were assessed with multiple linear regression. Atenolol was associated with increased glucose (1.8 ± 10.1mg/dl, P = 0.02) and decreased aMT6s (-4.5 ± 10.1 ng/mg, P < 0.0001). However, the aMT6s change was not correlated with post-atenolol glucose change. SNP rs11649514 in PRKCB was associated with glucose change (P = 1.0×10(-4)). PRKCB is involved in the melatonin-insulin regulatory pathway, and may be important in mediating clinically meaningful atenolol-related hyperglycemia.