Individual multi-locus heterozygosity is associated with lower morning plasma cortisol concentrations

Abstract

Objective: Stress is implicated as a risk factor for numerous illnesses in humans, putatively in part mediated by biological responses to stress, such as elevated cortisol concentrations. The theory of genetic homoeostasis suggests that individual heterozygosity facilitates compensation for environmental stresses. We hypothesized that heterozygosity ameliorates the biological response to a given level of perceived stress, reflected in lower plasma cortisol concentrations. Design: We examined the role of heterozygosity in the association between perceived psychological stress and morning cortisol concentrations in 854 individuals from the isolated island of Vis, Croatia. Methods: Cortisol concentrations were measured in morning plasma samples. A total of 1184 autosomal microsatellite markers were genotyped and individual multi-locus heterozygosity (MLH) was calculated as the proportion of heterozygous markers. The General Health Questionnaire with 30 items (GHQ-30) was used to assess the degree of psychological distress. Results: Mean MLH was 34.85G0.45% (range: 31.97-36.22%). Psychological distress (GHQ Likert score O31) was more prevalent in women (37 vs 18% in men, P!0.0001), in less educated people (bZK0.35 per year in school, P!0.001) and in lower socio-economic classes (bZK3.59, P!0.0001). Cortisol concentrations were positively associated with psychological distress (bZ2.20, PZ0.01). In a regression model adjusted for age, BMI, education and GHQ-30 score, MLH was independently and inversely associated with morning plasma cortisol concentrations (PZ0.005). Conclusion: More heterozygous individuals, as measured by microsatellite markers, had lower morning plasma cortisol concentrations for a given level of perceived psychological stress. This may be important, as higher cortisol concentrations may increase the allostatic load and be associated with a higher risk of stress-related illness.

Offspring Hormones Reflect the Maternal Prenatal Social Environment: Potential for Foetal Programming?

“…In particular, given that high testosterone levels can lead to increased aggression, one might expect concentrations of this hormone to be positively correlated with heterozygosity. Conversely, a negative association would be expected between cortisol and heterozygosity, as poor quality, relatively homozygous individuals should be more stressed than high quality, relatively heterozygous individuals [ 72 ]. However, neither HL nor sMLH were retained in any of our statistical models and, in contrast to the above predictions, maternal cortisol and testosterone were positively correlated.…”

Seasonal Vitamin D Status in Polish Elite Athletes in Relation to Sun Exposure and Oral Supplementation

“…Inadequate vitamin D status is common worldwide and might impact both the athletes’ health and performance [ 1 , 2 , 3 , 4 , 5 ]. Vitamin D is a nutrient that functions as a hormone precursor, which plays a crucial role in the regulation of calcium homeostasis and bone turnover and is therefore essential for musculoskeletal health [ 6 , 7 , 8 ]. The past two decades has seen a growing body of evidence indicating a possible pleiotropic effect across extraskeletal systems [ 4 , 6 ].…”

“…The dietary source of vitamin D is poor and approx. 90% of its supply originates from sunshine-induced skin synthesis which correlates with latitude, season of the year, time of day, age, skin melanine content and use of sun screens [ 4 , 8 ]. 25-hydroxyvitamin D– 25(OH)D is the best available biomarker of vitamin D status [ 7 , 8 , 16 ] although there is no consensus about its minimal level required in blood.…”

The effect of individual genetic heterozygosity on general homeostasis, heterosis and resilience in Siberian larch (Larix sibirica Ledeb.) using dendrochronology and microsatellite loci genotyping

“…Both heterosisandhomeostasishave beenstudiedin different organisms, includingtree species and usingdifferent traits and geneticmarkers, such asallozymes(e.g., Ledig et al, 1983;Mitton and Grant, 1984;Strauss, 1986;Bush et al, 1987;Strauss and Libby, 1987;Zouros et al,1988;Jelinski, 1993;Gonzalez-Varo et al, 2012), microsatellitesorso-calledsimple sequence repeats -SSRs (e.g., Abrahamsson et al, 2013;Zgaga et al,2013),as wellas single nucleotide polymorphisms-SNPs (e.g., Govindaraju et al,2009;Chelo and Teotonio, 2013).Correlation of IndHetwith various physiological, morphological and biochemicaltraits ofheterosisandhomeostasis(stable development)wasestimated in these studies.Traits used includedbilateral asymmetry(see Livshits and Kobyliansky, 1991;Parsons, 1992;Leung et al, 2000 for early reviews and more recent Kurbalija et al, 2011;Weisensee, 2013), growth rate (Ledig et al, 1983;Mitton and Grant, 1984;Strauss, 1986;Bush et al, 1987;Strauss and Libby, 1987;Zouros et al, 1988;Jelinski, 1993), and skeletal meristic traits (Zink et al, 1985).…”