Impact of obesity on infertility in women

Abstract

Review 111 IntroductionObesity, which is an important health issue, is a common problem among women of reproductive age. Obesity and overweight involves an abnormal and excessive fat accumulation that negatively affects the health of the body. According to the World Health Organization (WHO), if the body mass index (BMI) equals to or is greater than 25 kg/m 2 , it is considered overweight, whereas if the BMI equals to or is greater than 30 kg/m 2 , it is considered obesity (1). Obesity brings out many problems such as social, psychological, demographic, and health problems. It is related to increased health risks such as diabetes mellitus, hypertension, coronary heart disease, and osteoarthritis and is linked to various malignancies, particularly endometrium, breast, and colon cancers. Obesity also plays a significant role in reproductive disorders, particularly in women. It is associated with anovulation, menstrual disorders, infertility, difficulties in assisted reproduction, miscarriage, and adverse pregnancy outcomes. In obese women, gonadotropin secretion is affected because of the increased peripheral aromatization of androgens to estrogens. The insulin resistance and hyperinsulinemia in obese women leads to hyperandrogenemia. The sex hormone-binding globulin (SHBG), growth hormone (GH), and insulin-like growth factor binding proteins (IGFBP) are decreased and leptin levels are increased. Thus, the neuroregulation of the hypothalamic-pituitary-gonadal (HPG) axis deteriorates (2). These alterations may explain impaired ovulatory function and so reproductive health. Because of lower implantation and pregnancy rates, higher miscarriage rates, and increased maternal and fetal complications during pregnancy, obese women have a lower chance to give birth to a healthy newborn (3)(4)(5)(6). In this review, the effects of obesity on fertility and effective management of infertility in obese and overweight women is summarized. Epidemiology of obesityThe prevalence of obesity is increasing significantly worldwide. The International Obesity Task Force reported that 1,1 billion adults are overweight. They also reported that 312 million of them are obese (7). Approximately 3,4 million adults die each year because of health problems associated with obesity and being overweight. Of these, 44% of the problems are related to diabetes, 23% to ischemic heart disease, and between 7% and 41% to some malignancies associated with overweight and obesity (7). The prevelence of obesity has increased in developed countries because of a change in lifestyle, including reduced physical activity, changes in nutrition style, and an increased calorie intake (8). However, some other factors such as endocrine disorders, hormonal disorders, psychological disorders, and use of some drugs such as steroids and antidepressants may lead to obesity (9). The World Health Organization reported that 60% of women are overweight (≥25 kg/m 2 ) in the United States and most European countries and 30% of these are obese (≥30 kg/m 2 ) and 6% of these are mo...

Protective effect of resveratrol on spermatozoa function in male infertility induced by excess weight and obesity

“…When compared with the normal weight group, the underweight, overweight and obese groups exhibited a significant increase in DNA fragmentation rates. These results are consistent with those reported in previous studies (6–8). …”

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“…Such results suggest that extremes in body size such as thinness and overweight are a risk factor for ovulatory infertility (Buck et al ., 1996; Parihar, 2003). It is believed that anovulation occurs more frequently in obese than in normal weight women (Dağ & Dilbaz, 2015; Nelson & Fleming, 2007), and women of reproductive age with high BMI have a higher risk of ovulation problems (Pandey & Bhattacharya, 2010). …”

Computational and artificial neural network based study of functional SNPs of human LEPR protein associated with reproductive function

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