Conclusions
We found no evidence of a trade-off between somatic maintenance as measured by 8-OHdG and reproductive effort in women from this American population. On the contrary, higher gravidity and parity in premenopausal women was associated with lower damage to cellular DNA caused by oxidative stress. These results highlight the importance of population variation and environmental conditions when testing the occurrence of life-history trade-offs.
Methods
Serum samples and questionnaire data were collected from 63 premenopausal and postmenopausal women (mean age 53.4 years), controls in the Connecticut Thyroid Health Study, between May 2010 and December 2013. Samples were analyzed for levels of 8-OHdG and Cu/Zn-SOD using immunoassay method.
Results
Levels of oxidative damage (8-OHdG) but not oxidative defense (Cu/Zn-SOD) were negatively associated with parity and number of sons in premenopausal women (r = -0.52 for parity, r = -0.52 for number of sons, P < .01). Together, measures of reproductive effort, women's BMI, age, and menopausal status explained around 15% of variance in level of 8-OHdG. No association between reproductive effort characteristics and oxidative damage was found for postmenopausal women. Conclusions: We found no evidence of a trade-off between somatic maintenance as measured by 8-OHdG and reproductive effort in women from this American population. On the contrary, higher gravidity and parity in premenopausal women was associated with lower damage to cellular DNA caused by oxidative stress. These results highlight the importance of population variation and environmental conditions when testing the occurrence of life-history trade-offs.