Co-occurring obesity and smoking among U.S. women of reproductive age: Associations with educational attainment and health biomarkers and outcomes.

INTRODUCTION: Obesity and smoking are independently associated with socioeconomic disadvantage and adverse health effects in women of reproductive age and their children, but little is known about co-occurring obesity and smoking. The purpose of this study was to investigate relationships between co-occurring obesity and smoking, socioeconomic status, and health biomarkers and outcomes in a nationally representative sample. METHODS: Data from non-pregnant women of reproductive age were obtained from the U.S. National Health and Nutrition Examination Surveys reported between 2007 and 2010. Linear and logistic regressions were used to examine associations between obesity and smoking alone and in combination with educational attainment and a range of health biomarkers and outcomes. RESULTS: Prevalence of co-occurring obesity and smoking was 8.1% (~4.1 million U.S. women of reproductive age) and increased as an inverse function of educational attainment, with the least educated women being 11.6 times more likely to be obese smokers than the most educated. Compared to women with neither condition, obese smokers had significantly poorer cardiovascular and glycemic biomarker profiles, and higher rates of menstrual irregularity, hysterectomy, oophorectomy, physical limitations, and depression. Obese smokers also had significantly worse high-density lipoprotein (HDL) cholesterol levels, physical mobility, and depression scores than those with obesity or smoking alone. CONCLUSIONS: Co-occurring obesity and smoking is highly associated with low educational attainment, a marker of socioeconomic disadvantage, and a broad range of adverse health biomarkers and outcomes. Interventions specifically targeting co-occurring obesity and smoking are likely necessary in efforts to reduce health disparities among disadvantaged women and their children.

Maternal body mass index moderates the influence of smoking cessation on breast feeding.

INTRODUCTION: Smoking cessation is associated with greater breast feeding in newly postpartum women, while being overweight or obese is associated with lower rates of breast feeding. The purpose of this study is to examine whether the increases in breast feeding associated with smoking cessation are moderated by maternal body mass index (BMI). To our knowledge, the interaction of maternal smoking status and overweight/obesity on breast feeding has not been previously reported. METHODS: Participants (N = 370) were current or recent smokers at the start of prenatal care who participated in controlled trials on smoking cessation or relapse prevention during/after pregnancy. Study participants were followed from the start of prenatal care through 24 weeks postpartum. Smoking status was biochemically verified, and maternal reports of breast feeding were collected at 2-, 4-, 8-, 12-, and 24-week postpartum assessments. RESULTS: Women who reported postpartum smoking abstinence or had a normal/underweight prepregnancy BMI (<25) were more likely to be breast feeding at the time that smoking status was ascertained (odds ratio [OR] = 3.02, confidence interval [CI] = 2.09-4.36, and OR = 2.07, CI = 1.37-3.12, respectively). However, smoking status and BMI interacted such that (a) normal/underweight women showed a stronger association between smoking abstinence and breast feeding (OR = 4.58, CI = 2.73-7.66) than overweight/obese women (OR = 1.89, CI = 1.11-3.23), and (b) abstainers showed an association between normal/underweight BMI and breast feeding (OR = 3.53, CI = 1.96-6.37), but smokers did not (OR = 1.46, CI = 0.88-2.44). CONCLUSIONS: Overweight/obesity attenuates the positive relationship between smoking abstinence and greater breast feeding among newly postpartum women.

Voiding function in obese and type 2 diabetic female rats.

The effects of obesity and type 2 diabetes (DMII) on the lower urinary tract (LUT) were characterized by evaluating voiding function and anatomy in female Zucker diabetic fatty (ZDF) rats. Age-matched female virgin rats were separated into three experimental groups: Zucker lean rats (control; normal diet, n = 22), ZDF rats (obese+nondiabetic; low-fat diet, n = 22), and ZDF rats (obese+diabetic; high-fat diet, n = 20). Rats were placed on their specified diet for 10 wk before urodynamic LUT evaluation. A suprapubic catheter was implanted 2 days before urodynamic studies. Voiding function was evaluated by cystometric and leak point pressure (LPP) testing. The bladder, urethra, and vagina were immediately excised for qualitative histological evaluation. Compared with control rats, obese+nondiabetic and obese+diabetic rats had significantly decreased contraction pressure (P = 0.003) and increased cystometric filling volume (P < 0.001). Both obese groups exhibited significantly higher voided volumes (P = 0.003), less frequent urinary events (P < 0.001), and increased residual volumes (P = 0.039). LPP studies showed a nonsignificant decrease in LPP (P = 0.075) and baseline pressure (P = 0.168) in both obese groups compared with control. Histology of the external urethral sphincter in obese rats showed increased fibrosis, leading to disruption of the skeletal muscle structure compared with control. Additionally, the bladder wall of the obese+nondiabetic and obese+diabetic rats demonstrated edema and vasculopathy. Voiding dysfunction was evident in both obese groups but with no significant differences due to DMII, suggesting that voiding dysfunction in DMII may be attributable at least in part to chronic obesity.

The impact of cesarean delivery on pelvic floor dysfunction in lysyl oxidase like-1 knockout mice.

OBJECTIVE: : Lysyl oxidase like-1 (LOXL1) knockout mice have abnormal elastic fiber homeostasis and frequently develop pelvic floor dysfunction after pregnancy and delivery. The objective of this study was to test the hypothesis that tissue changes associated with vaginal delivery lead to pelvic floor dysfunction as a result of abnormal elastic fiber homeostasis. METHODS: : Female LOXL1 knockout mice delivered either spontaneously or by cesarean delivery. Mice were assessed weekly for pelvic organ prolapse (POP). At 12 weeks postpartum, lower urinary tract function was assessed by cystometry and leak-point pressure testing. Urethrovaginal cross-sections were analyzed using a histologic grading scale to assess elastin fiber disorganization. RESULTS: : A total of 39 mice delivered by spontaneous vaginal delivery and 36 by cesarean delivery. Twelve weeks after spontaneous vaginal delivery or cesarean delivery, 23 (59%) and 11 (31%) mice had developed POP, respectively. The mean time to develop POP was 7.2 weeks after spontaneous vaginal delivery and 10.5 weeks after cesarean delivery (log rank, P = 0.0008). The Cox proportional hazard ratio was 0.55 (95% confidence interval, 0.38-0.79). Mice with POP had increased frequency of bladder contractions not associated with voiding during cystometry (P = 0.02). POP, but not mode of delivery, was associated with increased elastic fiber disorganization. CONCLUSIONS: : Cesarean delivery delays the development of POP in LOXL1 knockout mice. POP is associated with increased bladder contraction frequency and increased elastic fiber disorganization in the urethra and vagina. The mechanisms underlying these findings warrant further investigation.

Lower urogenital tract anatomical and functional phenotype in lysyl oxidase like-1 knockout mice resembles female pelvic floor dysfunction in humans.

Female pelvic floor dysfunction (FPFD) is a complex group of conditions that include urinary incontinence and pelvic organ prolapse (POP). In humans, elastin homeostasis has been implicated in the pathophysiology of FPFD. Lysyl oxidase-like 1 knockout (LOXL1-KO) mice demonstrate abnormal elastic fiber homeostasis and develop FPFD after parturition. We compared the lower urogenital tract (LUT) anatomy and function in LOXL1-KO mice with and without POP. LUT anatomy was assessed in LOXL1-KO mice over 28 wk. Pelvic visceral anatomy in LOXL1-KO was evaluated with a 7-Tesla magnetic resonance imaging (MRI) scanner. LUT function was assessed using conscious cystometry and leak point pressure (LPP) testing. Quantitative histological analysis of elastic fibers was performed on external urethral sphincter (EUS) cross sections. By 25 wk of age, 50% of parous LOXL1-KO mice developed POP. LOXL1-KO mice with POP had greater variability in the size and location of the bladder on MRI compared with mice without POP. Parity and POP were associated with lower LPP. Elastin clusters were significantly increased in the EUS of LOXL1-KO mice with POP. Because parity triggers POP in LOXL1-KO mice, LOXL1-KO mice with POP have variable internal pelvic anatomy, and both parity and POP are associated with a decrease in LPP, we conclude that LOXL1 LUT anatomical and functional phenotype resembles FPFD in humans. The increase in elastin clusters in the urethra of LOXL1-KO mice with POP suggests that elastin disorganization may lead to functional abnormalities. We conclude that LOXL1 warrants further investigation in the pathphysiology of FPFD.

Brain orexins and wake regulation in rats exposed to maternal deprivation.

Maternal deprivation (MD) is a neonatal stressor that leads to behavioral and molecular manifestations of chronic stress in adulthood. Recent evidence has suggested that stress may impact wake regulation through corticotropin-releasing hormone (CRH) and the orexinergic system. We studied the wake/sleep features and brain levels of orexin and orexin receptors in adult rats neonatally subjected to either ten days of MD or a control procedure from postnatal day 4. At 3 months of age, one set of rats from both groups underwent 48 h of polysomnographic recording. All rats (including those that did not undergo surgery) were subsequently sacrificed for ELISA, radioimmunoassay and western blot measurement of orexins, orexin receptors and CRH in multiple brain regions. Neonatal MD induced an increase of total wake time (decreased total sleep) during the light period, which corresponds to human night time. This increase was specifically composed of quiet wake, while a small but significant decrease of active wake was observed during the dark period. At the molecular level, MD led to increased hypothalamic CRH and orexin A, and frontal cortical orexin 1 receptors (OX1R). However, hippocampal orexin B was reduced in the MD group. Our study discovered for the first time that the adult MD rat has sleep and neurobiological features of hyperarousal, which is typical in human insomnia. We concluded that neonatal MD produces adult hyperarousal in sleep physiology and neurobiology, and that the adult MD rat could be a model of insomnia with an orexinergic mechanism.