Association between Opioid Receptor mu 1 (OPRM1) Gene Polymorphisms and Tobacco and Alcohol Consumption in a Spanish Population

Abstract

Evidence gained from animals and humans suggests that the encephalic opioid system might be involved in the development of drug addiction through its role in reward. Our aim is to assess the influence of genetic variations in the opioid receptor mu 1 on alcohol and tobacco consumption in a Spanish population. 763 unrelated individuals (465 women, 298 men) aged 18-85 years were recruited between October 2011 and April 2012. Participants were requested to answer a 35-item questionnaire on tobacco and alcohol consumption, as well as to complete the AUDIT and Fagerström tests. Individuals were genotyped for three polymorphisms in the opioid receptor mu 1 (OPRM1) gene, using a TaqMan protocol. In males, the rs10485057 polymorphism was associated with total pure ethanol intake and with the risk of being an alcohol consumer. Also, this polymorphism was significantly associated with higher Fagerström scores. Rs1799971 had a different influence on adaptive and maladaptive patterns of alcohol use. Despite the limited sample size, our study might enrich current knowledge on patterns of alcohol use, because it encompasses both extreme and adaptive phenotypes, providing thus a wider perspective on this subject.

Lack of associations of the opioid receptor mu 1 (OPRM1) A118G polymorphism (rs1799971) with alcohol dependence: review and meta-analysis of retrospective controlled studies

“…17 studies with 9613 patients were included. [ 15 – 31 ] Nine studies involved Caucasian subjects and were done in the USA, [ 15 , 16 , 24 , 28 , 30 ] Germany, [ 19 , 22 , 27 ] and Spain [ 18 ] (8026 subjects in total). Eight involved Asian subjects and were done in China, [ 23 , 26 , 29 , 31 ] India, [ 17 ] Japan, [ 25 ] and Korea [ 20 , 21 ] (1587 subjects in total).…”

“…Genotyping methods used included direct sequencing, polymerase chain reaction-restricted fragment length polymorphisms (PCR-RFLP), Puregene™ kit or standard phenol-chloroform method, TaqMan assay, and fluorescence resonance energy transfer method. Ten matchings for the controls were population-based, [ 15 , 16 , 18 , 24 – 29 , 31 ] 3 were hospital-based, [ 20 – 22 ] and 4 were mixed. [ 17 , 19 , 23 , 30 ] The characteristics and methodological qualities are in Table 5 .…”

“…[ 39 ] Recently, Frances et al found that the OPRM1 A118G polymorphism (A > G) was associated with alcohol/tobacco-dependence in a Spanish population, and this association was related to several environmental and genetic factors. [ 18 ] However, the study from Rouvinen-Lagerstrom et al suggested that the effect of A118G-polymorphism on the development of alcohol dependence was not statistically significant ( P > 0.05). [ 40 ] In a study by Franke et al, data from ethnically homogenous samples detected no actual difference of the OPRM1 A118G polymorphism between alcohol dependent subjects and controls.…”

Association of opioid receptor mu 1 (OPRM1) A118G polymorphism (rs1799971) with nicotine dependence

“…Figure 1 outlines the literature search process. Based on the inclusion criteria set in Table 1 , a total of seven articles involving 3313 patients were finally included [ 5 , 7 – 11 ], among which four studies [ 5 , 7 , 10 ] involved predominantly white patients in the USA, Norway, and Spain (1596 cases in total). Three involved predominantly Asian patients [ 8 , 9 , 11 ] in mainland China [ 9 , 11 ] and Taiwan [ 8 ] (1717 cases in total).…”

“…Nicotine consumption can lead to increased endogenous opioids, especially β-endorphin. The binding of β-endorphin to μ-opioid receptors (genetic locus OPRM1) might reinforce nicotine dependence by increasing dopamine actions in reward centers [ 5 , 6 ]. As suspected in the case of alcohol, genetic variations of OPRM1 might impact the risk of developing nicotine dependence.…”