High Intake of Energy and Fat in Southwest Chinese Women with PCOS: A Population-Based Case-Control Study

May High Intake of Energy and Fat in Southwest Chinese Women with PCOS: A Population- Based Case-Control Study Jing Zhang 0 1 2 3 Ying Liu 0 1 2 3 Xiaofang Liu 0 1 2 3 Liangzhi Xu 0 1 2 3 Lingling Zhou 0 1 2 3 Liulin Tang 0 1 2 3 Jing Zhuang 0 1 2 3 Wenqi Guo 0 1 2 3 Rong Hu 0 1 2 3 0 Funding: This research was supported by National Natural Science Foundation of China (81270665, 41473097); Scientific Research Foundation of Health Department of Sichuan province (100377 , 060020, 090289) , China; Science and Technology Basic platform foundation of Sichuan Province (2012JCPT009) , China 1 Data Availability Statement: All relevant data are within the paper 2 Academic Editor: Yang Yu, Peking University Third Hospital , CHINA 3 1 Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University , Chengdu, Sichuan , People's Republic of China, 2 Department of Ultrasound, West China Second University Hospital, Sichuan University , Chengdu, Sichuan , People's Republic of China, 3 Clinical Laboratory center, West China Second University Hospital, Sichuan University , Chengdu, Sichuan , People's Republic of China - Competing Interests: The authors have declared that no competing interests exist. Polycystic ovary syndrome (PCOS) is a common reproductive endocrinological disease with heterogeneous phenotype. Obesity contributes to the increased prevalence and severity of PCOS. Whether the intakes of major nutrients are higher in Chinese PCOS patients is still unknown. To study the intakes of total energy, protein, fat and carbohydrate in Southwest Chinese PCOS patients. 1854 women were included in the cross-sectional study. A population-based case-control study was conducted. The dietary habits and nutrients intake status of 169 PCOS patients and 338 age-matched controls were investigated by the method of semi-quantitative food frequency questionnaire. The actual intake of total energy (P = 0.01) and fat (P = 0.01) were higher, but carbohydrate was lower (P = 0.01) in PCOS patients as compared with the controls. The energy percentage supplied by protein (12.33%2.27% vs. 19.26%5.91%, P<0.001) and carbohydrate (48.72%6.41% vs. 68.31%8.37%, P<0.001) were lower in Southwest Chinese PCOS patients than those of control, however, the energy percentage supplied by fat was higher (38.95%5.71% vs. 12.42%5.13%, P<0.001) in PCOS. Limit the intake of total energy and fat shall be recommended to the Southwest Chinese PCOS patients. Women with PCOS in Southwest China shall consult with the nutritionist for improving the dietary structure. Polycystic ovary syndrome (PCOS) is a common but complex reproductive endocrinology disease, affecting both the adolescent and reproductive women. It involves reproductive system, endocrinologic system, metabolic system, gynecological cancer and obstetric events, which are characterized by irregular menstrual cycle, infertility, hirsutism, acne, obesity, insulin resistance, diabetes mellitus, dyslipidemia, endometrium carcinoma, gestational diabetes mellitus and preterm delivery [1]. PCOS may occur from the adolescence, and continues to the menopause, having a strong impact on the life quality of the whole life and the population quality of the offspring. Obesity is a prevalent characteristic of PCOS, with a pooled estimated prevalence of 49% [2]. Abdominal adiposity, obesity, and insulin resistance (IR) are involved in the pathogenesis of PCOS. There may be a bidirectional interaction between PCOS and weight, with PCOS driving weight gain and weight gain contributing to an increased prevalence and severity of PCOS [3]. Obesity may deteriorate the severity of menstrual irregularity and insulin resistance, and may have significant impact on the long-term health risks and reproduction function of PCOS women. Progressive worsening of insulin resistance with age is primarily driven by the increase of body mass index (BMI) and may contribute to the higher risk of type 2 diabetes mellitus (T2DM) in women with PCOS [4]. Given the association between obesity, insulin resistance and the presentation of PCOS, weight management is a key initial treatment strategy for PCOS which can improve the reproductive, metabolic and psychological performance [1]. Nutritional and dietary factors are speculated to be the risk factors for PCOS. Women with PCOS may additionally have increased intake of high glycemic index (GI) foods [5] and reduced physical activity [6]. However, no difference in energy, dietary intake, physical activity or muscle strength is found between lean or overweight women with or without PCOS in some studies [5, 78]. The BMI varies considerably across countries for women with PCOS. There is a lower BMI in Chinese women with PCOS as compared with Caucasian population [9]. The dietary composition varies among population with different race and territory. The dietary situation of Chinese PCOS patients is unclear. Whether the intakes of major nutrients supplying energy are higher in Chinese PCOS patients is still unknown. The intakes of total energy, protein, fat and carbohydrates were investigated between Chinese women with PCOS and control women in present study to clarify the relationship among them. A population-based case-control study was carried out in Chengdu, Sichuan. The study protocol of the cross-sectional survey has already been partly published in our previous article including sample size calculation, random cluster sampling, participants selection, questionnaire investigation, ultrasound examination, blood collection and experimental tests [10]. Sample size calculation was based on the primary outcome of the prior study assessing the prevalence of PCOS among women in Chengdu. Because the prevalence of PCOS differed greatly in different age groups and regions, we chose a moderate prevalence (P0 = 0.04) for sample size calculation. The calculated sample size was 1475. Considering a dropout rate of 10%, our final sample size was 1623. The age constituent ratio of women obtained from the population census in the 2004 Yearbook of Sichuan Province was used to calculate the number of participants needed in each age group. Five communities, two universities and three middle schools from nine districts of Chengdu city were randomly cluster sampled to collect the participants. The PCOS patients identified from the cross-sectional study were collected as the case group in the case-control study. The control number was calculated based on the number of PCOS patients with the ratio of 1:2 in each age group, respectively. The study was approved by the Human Ethics Committee of West China Second University Hospital. Information and consent forms were obtained from all the subjects or their guardians. 1854 women, aged 1244 years, who have had menses for at least 2 years, who have lived in Chengdu for at least 6 months, and who agree to answer the questionnaires were included in the cross-sectional study. Participants who h (...truncated)