Physical activity and the risk of breast cancer among Nigerian women

BackgroundAlthough physical activity has been associated with a reduced risk of breast cancer risk in high income countries (HIC), its role has not been widely studied in sub-Saharan Africa. Our aim was to investigate the association between physical activity (PA) and the risk of breast cancer in Nigeria.MethodsWe conducted a hospital-based case-control study involving participants from five hospitals in Lagos and Abuja. Women were interviewed in-person between October 2016 and May 2017 using a semi-structured questionnaire. Total PA was estimated by summing occupational, household, transport and leisure PA scores. PA was summarised as metabolic equivalents (MET) hours per week (MET-hr/wk). The putative association between breast cancer incidence and PA was analysed using multivariable logistic regression.Results379 histologically confirmed breast cancer cases and 403 controls took part. Compared to women in the lowest categories, women in the upper middle category of total PA(adjusted OR-AOR 0.44, 95% CI: 0.27, 0.78),uppermost categories of total non-vigorous PA (AOR 0.26, 95%CI:0.09,0.75), household PA(AOR 0.0.38, 95% CI: 0.20, 0.71) and occupational PA (AOR 0.64, 95% 0.40, 1.02) had a reduced risk of breast cancer following adjustment for relevant confounders. Transport and leisure PA were not significantly associated with a reduced risk of breast cancer.ConclusionThe total effect of various PA related to regular activities of Nigerian women was associated with a reduced risk of breast cancer. PA especially at household and occupational environments should be promoted as part of breast cancer prevention strategy in Nigeria.     

Front-to-back & dabbing wiping behaviour post-toilet associated with anal neoplasia & HR-HPV carriage in women with previous HPV-mediated gynaecological neoplasia

BackgroundAnal cancer is a human papillomavirus (HPV)-mediated neoplasia of the anal squamous epithelium. Anal cancer is much more common among women, particularly those with a previous high-grade gynaecological neoplasia.MethodsCross-sectional study of women with a previous HPV-mediated gynaecological neoplasia in Tasmania, Australia. Women presenting for follow-up gynaecological care had anal swab samples taken for anal cytology by Hologic Liquid ThinPrep, followed by HPV genotyping. Women with abnormal anal cytology were invited for high-resolution anoscopy. Potential risk factors, including post-toilet wiping behaviours, were queried by questionnaire while clinical covariates were extracted from medical records. Covariates of anal outcomes evaluated by log-binomial and log-multinomial regression.ResultsFrom 163 women enrolled in the study, 65 (39.9%) had abnormal cytology, with 46 (28.2%) being high-grade. Of the 50 women with abnormal anal cytology having high-resolution anoscopy, 32 (64.0%) had abnormal histology with 13 (26.0%) being high-grade. Of the 123 women tested for HR-HPV DNA, 48 (39.0%) had HR-HPV detected, the most common genotypes being 16 and 51 (14/123, 11.4% for both).In addition to some known anal cancer risk factors, we found front-to-back wiping was associated with significantly increased (Prevalence ratio (PR) range: 1.99⿿3.60) prevalence of cytological and histological abnormality and HR-HPV carriage/co-carriage, while dabbing post-toilet was significantly associated with decreased prevalences (PR range: 0.50⿿0.62).ConclusionsPost-toilet wiping behaviours were significantly associated with the prevalence of anal cytological, histological and HR-HPV carriage outcomes. This suggests a biologically plausible mechanism for HR-HPV introduction and the higher frequencies of anal neoplasia in women.     

Laminaria augmentation of intra-amniotic PGF2α for midtrimester pregnancy termination

In our hands, intra-amniotic PGF₂α 40 mg for midtrimester pregnancy termination had a mean infusion to abortion interval of 29.4 hr. However, pretreatment of 230 patients with laminaria tents inserted 14–18 hr before PGF₂α infusion resulted in a dramatically reduced time to abortion (14.3 hr mean) with a low incidence of gastrointestinal and other side effects. Laminaria tents inserted at the same time as PGF₂α infusion in 26 patients also resulted in reduced time to abortion (18.6 hr mean). In the laminaria pretreated group, the infusion to abortion interval was indirectly related to the number of laminaria inserted and not to the nulliparous or parous state. Although we have made significant strides in shortening the abortion interval in the hospital, retained placentae and blood loss persist as problems related to the use of prostaglandin for abortion.     

Accumulation of Mercury in Ovaries of Mice After the Application of Skin-lightening Creams

Skin-lightening creams are being increasingly used by women in particular, worldwide in an attempt to whiten their skin. Men and older people use these creams to remove age spots or other pigmentation disorders. Several studies have reported the presence of high mercury levels in skin-lightening cream. Women, especially pregnant and nursing mothers, who use these creams are at risk of mercury toxicity because long-term exposure can cause permanent neurological damage, nephrological disorders, fertility problems, and birth defects. Early exposure usually has no clinical symptoms. Mercury levels were measured in a total of 49 ovary tissue samples. The mean mercury contents in the ovaries of non-treated mice (11.70 ± 13.38 ng/g) were compared to mice treated with Rose skin-lightening cream samples (2,471.92 ± 1,336.31 ng/g) and those treated with Fair & Lovely skin-lightening creams (58.47 ± 39.51 ng/g). The mercury content in the ovary tissues increased with number of cream applications and were highest in the ovaries of mice treated twice a day with Fair & Lovely (87.79 ± 26.20 ng/g) and once a day with Rose (3,515.61 ± 1,099.78 ng/g). Our data indicate that dermal exposure to mercury can result in a significant accumulation in the ovaries of mice following the application of skin-lightening cream. This may cause alterations in reproductive behavior and contribute to infertility or ovarian failure. Of course, these results need to be confirmed by further research. Imported or locally made skin-lightening creams are widely available in Saudi market. It would be ideal to ban the sale of these creams but unfortunately, advertisements in the mass media presenting celebrities and beauty specialists make these products more popular. Alternatively, public health authorities should encourage more reliance on prescribed creams for the treatment of skin pigmentation problems.     

Common carotid artery stiffness, cardiovascular function and lipid metabolism after menopause

While cardiovascular disease is a major cause of death in elderly women, relatively little is known regarding the influence of menopause on atherogenesis. We tried to characterize postmenopausal changes in the arterial properties. A group of 72 postmenopausal women were classified into subgroups based on duration of the postmenopausal period (PMP): Group PM1 (1-2 years; n = 16), PM4 (2-6 years; n = 16), PM8 (6-10 years; n = 25), and PM12 (10-15 years; n = 15). The control group consisted of 24 volunteers with regular menstruation (PM0). The diameter pulse waveform and intima-media thickness (IMT) of the common carotid artery (CCA) was measured using a phase-locked echo tracking system coupled with B-mode ultrasonography. The stiffness index was calculated from the waveform and the systemic blood pressure. The cardiac contractile force and the cerebral perfusion were also estimated using the maximum incremental velocity (MIV) and the calculated blood flow, as well as the fasting lipid profile. When compared to control, significant and progressive increases were noted in total cholesterol and low density lipoprotein (PM1, PM4, PM8, PM12), IMT (PM8, PM12), and SI (PM1, PM4, PM8, PM12). Further significant and progressive reductions were noted in pulse amplitude of CCA diameter (PM1, PM4, PM8, PM12) and MIV and cerebral perfusion (PM8, PM12). The postmenopausal increase in CCA stiffness as well as lipid profile occurs earlier than the increase in IMT and may be a more sensitive predictor of disorder on arterial property.     

Rapid infant weight gain predicts childhood overweight

Objective : To determine among a contemporary cohort whether rapid weight gain between birth and 6 months is associated with risk of childhood overweight and if this risk differs by ethnicity and/or breast‐feeding history. Research Methods and Procedures : This was a cross‐sectional survey in 1999 to 2000 of parents/guardians of children participating in the Special Supplemental Nutrition Program for Women, Infants, and Children in New York State. Measurements were abstracted by chart review, including weight at birth and 6 months, and height and weight at time of survey and every 6 months subsequently. Overweight at 4 years of age was defined as a BMI ≥ 95th age‐ and sex‐specific percentiles. Results : The study sample was 32% Hispanic, 19% black, and 49% white; 17% of children were overweight. Rate of infant weight gain (expressed in terms of 100 g/mo) was significantly associated with being overweight at 4 years (odds ratio, 1.4; 95% confidence interval, 1.3 to 1.6 after adjusting for history of breast‐feeding, birth weight, and ethnicity). The odds of being overweight at 4 years of age for Hispanic children were twice those of non‐Hispanic children (odds ratio, 2.2; 95% confidence interval, 1.5 to 3.3). The population‐attributable risk of overweight at 4 years of age was 19% for children in the highest quintile of infant weight gain. Discussion : Among this contemporary, multi‐ethnic cohort, rapid infant weight gain was associated with increased risk of being overweight at 4 years of age, independently of potential confounders. Identification of the risk factors contributing to rapid weight gain during infancy might improve early recognition and guide strategies for optimal nutrition to prevent the development of childhood overweight.     

INCREASED SENSITIVITY TO LIGHT-INDUCED MELATONIN SUPPRESSION IN PREMENSTRUAL DYSPHORIC DISORDER

Increased sensitivity to light-induced melatonin suppression characterizes some, but not all, patients with bipolar illness or seasonal affective disorder. The aim of this study was to test the hypothesis that patients with premenstrual dysphoric disorder (PMDD), categorized as a depressive disorder in Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), have altered sensitivity to 200 lux light during mid-follicular (MF) and late-luteal (LL) menstrual cycle phases compared with normal control (NC) women. As an extension of a pilot study in which the authors administered 500 lux to 8 PMDD and 5 NC subjects, in the present study the authors administered 200 lux to 10 PMDD and 13 NC subjects during MF and LL menstrual cycle phases. Subjects were admitted to the General Clinical Research Center (GCRC) in dim light (<50 lux) to dark (during sleep) conditions at 16:00?h where nurses inserted an intravenous catheter at 17:00?h and collected plasma samples for melatonin at 30-min intervals from 18:00 to 10:00?h, including between 00:00 and 01:00?h for baseline values, between 01:30 and 03:00?h during the 200 lux light exposure administered from 01:00 to 03:00?h, and at 03:30 and 04:00?h after the light exposure. Median % melatonin suppression was significantly greater in PMDD (30.8%) versus NC (?0.2%) women (p?=?.040), and was significantly greater in PMDD in the MF (30.8%) than in the LL (?0.15%) phase (p?=?.047). Additionally, in the LL (but not the MF) phase, % suppression after 200 lux light was significantly positively correlated with serum estradiol level (p ?=? .007) in PMDD patients, but not in NC subjects (p?>?.05). (Author correspondence: bparry@ucsd.edu)     

Women's sexual arousal: effects of high alcohol dosages and self-control instructions

The basic relationship between alcohol and women's sexual arousal – especially genital arousal – received little research attention for nearly 30 years (e.g. Wilson and Lawson, 1978) until very recently (e.g. George et al., 2009). To investigate hypotheses based on earlier findings and Alcohol Myopia Theory (AMT), two experiments evaluated the effects of high blood alcohol concentrations (BACs) and arousal instructional demands on indices of vaginal responding and self-reported sexual arousal. In Experiment 1, self-control instructions to maximize (versus suppress) arousal increased peak and average Vaginal Pulse Amplitude (VPA) change. Self-control also interacted with a target BAC of .08% (versus .00%) to influence latency to peak arousal onset: Intoxicated women instructed to maximize showed a shorter latency to peak arousal than did intoxicated women instructed to suppress; however, sober women showed an undifferentiated pattern. Also, in Experiment 1, the target BAC of .08% had no effect on VPA or subjective arousal measures. In Experiment 2, a target BAC of .10% (versus .00%) attenuated peak change and average change in VPA, but this dosage had no effects on latency to peak achieved arousal, or on subjective arousal. Instructions to maximize arousal (versus no instruction) had no effect on any arousal measures. Overall, among young moderate drinking women, alcohol had attenuating effects but only at the higher dosage. Maximize versus suppress instructions about arousal had predicted effects on arousal and interactive effects on latency, but only at the lower dosage. The findings highlight the importance of dosage and contextual factors in alcohol's impact on the variability of women's sexual responding.     

Associations between functional polymorphisms in antioxidant defense genes and urinary oxidative stress biomarkers in healthy, premenopausal women

Functional polymorphisms in endogenous antioxidant defense genes including manganese superoxide dismutase (MnSOD), catalase (CAT), and glutathione peroxidase (GPX-1) have been linked with risk of cancer at multiple sites. Although it is presumed that these germline variants impact disease risk by altering the host’s ability to detoxify mutagenic reactive oxygen species, very few studies have directly examined this hypothesis. Concentrations of 8-isoprostane F2α (8-iso-PGF2α) and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxoxdG)—sensitive indicators of lipid peroxidation and DNA oxidation, respectively—were measured in 24-h urine samples obtained from 93 healthy, premenopausal women participating in a dietary intervention trial. In addition, DNA was extracted from blood for genotyping of MnSOD Val16Ala, CAT-262 C > T, and GPX1 Pro198Leu genotypes by Taqman assay. Although geometric mean concentrations of 8-iso-PGF2_α and 8-oxoxdG varied across several study characteristics including race, education level, body mass index, and serum antioxidant levels, there was little evidence that these biomarkers differed across any of the examined genotypes. In summary, functional polymorphisms in endogenous antioxidant defense genes do not appear to be strongly associated with systemic oxidative stress levels in young, healthy women.     

Effect of 120 days of bed-rest with and without countermeasures on the mechanical properties of the triceps surae muscle in young women

The effect of a 120-day 6° head-down tilt (HDT) bed rest with and without countermeasures on the mechanical properties of the human triceps surae muscle was studied in eight healthy young women subjects. One group [n = 4, mean age 31.5 (SEM 1.7) years] underwent a 120-day HDT only and a second group [n = 4; mean age 28.0 (SEM 1.1) years] underwent HDT with countermeasures (physical training). The results showed that the contractile properties of the skeletal muscle studied changed considerably. After HDT without countermeasures the maximal voluntary contraction (MVC) had decreased by 36% (P < 0.05), and the electrically evoked tetanic tension at 150 Hz (P _o) and isometric twitch contraction (P _t) had decreased by 24% (P < 0.02) and 12% (P < 0.05), respectively. Time- to-peak tension (TPT) of the twitch had significantly increased by 14% (P<0.05), but half-relaxation time (1/2RT), and total contraction time (TCT) had decreased by 19% (P<0.05) and 18% (P<0.05), respectively. The difference between P _o and MVC expressed as a percentage of P _o and referred to as force deficiency (FD), was also calculated. The FD had increased by 40% (P<0.001). The rate of increase of voluntary contractions calculated according to a relative scale had significantly reduced, but for the electrically evoked contraction no substantial changes were observed. After HDT with countermeasures TPT, 1/2RT and TCT of the twitch had decreased by 4%, 7%, 19%, respectively in relation to the control condition. Training had caused a decrease of 3% (P>0.05) in MVC, and P _t, and in P _o of 14%, and of 9% (P>0.05), respectively. The FD had decreased significantly by 10% (P<0.02). The rate of increase of electrically evoked tetanic tension did not change significantly during HDT with countermeasures but the rate of increase in isometric voluntary tension development was increased. Physical training provided a reserve of neuromuscular function, which attenuated the effect of bed rest. The experimental findings indicated that neural as well as muscle adaptation occurred in response to HDT with countermeasures. Accepted: 7 November 1997