The association of women's birth size with risk of molecular breast cancer subtypes: a cohort study.

BACKGROUND: Because birth size appears to be positively associated with breast cancer risk, we have studied whether this risk may differ according to molecular breast cancer subtypes. METHODS: A cohort of 22,931 women born 1920-1966 were followed up for breast cancer occurrence from 1961 to 2012, and 870 were diagnosed during follow-up. Archival diagnostic material from 537 patients was available to determine molecular breast cancer subtype, specified as Luminal A, Luminal B (human epidermal growth factor receptor 2 (HER2)-), Luminal B (HER2+), HER2 type, and Triple negative (TN) breast cancer. Information on the women's birth weight, birth length and head circumference at birth was used to estimate hazard ratios (HR) with 95% confidence intervals (CI) for each molecular subtype, applying Cox regression, and stratified by maternal height. RESULTS: Birth length (per 2 cm increments) was positively associated with Luminal A (HR = 1.2, 95% CI, 1.0-1.3), Luminal B (HER2+) (HR = 1.3, 95% CI, 1.0-1.7), and TN breast cancer (HR = 1.4, 95% CI, 1.0-1.9). No clear association was found for birth weight and head circumference. The positive associations of birth length were restricted to women whose mothers were relatively tall (above population median). CONCLUSION: We found a positive association of birth length with risk of Luminal A, Luminal B (HER2+) and TN breast cancer that appears to be restricted to women whose mothers were relatively tall. This may support the hypothesis that breast cancer risk is influenced by determinants of longitudinal growth and that this finding deserves further scrutiny.

Physical activity and the risk of heart failure: a systematic review and dose-response meta-analysis of prospective studies.

Although physical activity is an established protective factor for cardiovascular diseases such as ischemic heart disease and stroke, less is known with regard to the association between specific domains of physical activity and heart failure, as well as the association between cardiorespiratory fitness and heart failure. We conducted a systematic review and meta-analysis of prospective observational studies to clarify the relations of total physical activity, domains of physical activity and cardiorespiratory fitness to risk of heart failure. PubMed and Embase databases were searched up to January 14th, 2020. Summary relative risks (RRs) were calculated using random effects models. Twenty-nine prospective studies (36 publications) were included in the review. The summary RRs for high versus low levels were 0.77 (95% CI 0.70-0.85, I2 = 49%, n = 7) for total physical activity, 0.74 (95% CI 0.68-0.81, I2 = 88.1%, n = 16) for leisure-time activity, 0.66 (95% CI 0.59-0.74, I2 = 0%, n = 2) for vigorous activity, 0.81 (95% CI 0.69-0.94, I2 = 86%, n = 3) for walking and bicycling combined, 0.90 (95% CI 0.86-0.95, I2 = 0%, n = 3) for occupational activity, and 0.31 (95% CI 0.19-0.49, I2 = 96%, n = 6) for cardiorespiratory fitness. In dose-response analyses, the summary RRs were 0.89 (95% CI 0.83-0.95, I2 = 67%, n = 4) per 20 MET-hours per day of total activity and 0.71 (95% CI 0.65-0.78, I2 = 85%, n = 11) per 20 MET-hours per week of leisure-time activity. Nonlinear associations were observed in both analyses with a flattening of the dose-response curve at 15-20 MET-hours/week for leisure-time activity. These findings suggest that high levels of total physical activity, leisure-time activity, vigorous activity, occupational activity, walking and bicycling combined and cardiorespiratory fitness are associated with reduced risk of developing heart failure.

Low thyroid function is not associated with an accelerated deterioration in renal function.

BACKGROUND: Chronic kidney disease (CKD) is frequently accompanied by thyroid hormone dysfunction. It is currently unclear whether these alterations are the cause or consequence of CKD. This study aimed at studying the effect of thyroid hormone alterations on renal function in cross-sectional and longitudinal analyses in individuals from all adult age groups. METHODS: Individual participant data (IPD) from 16 independent cohorts having measured thyroid stimulating hormone, free thyroxine levels and creatinine levels were included. Thyroid hormone status was defined using clinical cut-off values. Estimated glomerular filtration rates (eGFR) were calculated by means of the four-variable Modification of Diet in Renal Disease (MDRD) formula. For this IPD meta-analysis, eGFR at baseline and eGFR change during follow-up were computed by fitting linear regression models and linear mixed models in each cohort separately. Effect estimates were pooled using random effects models. RESULTS: A total of 72 856 individuals from 16 different cohorts were included. At baseline, individuals with overt hypothyroidism (n = 704) and subclinical hypothyroidism (n = 3356) had a average (95% confidence interval) -4.07 (-6.37 to -1.78) and -2.40 (-3.78 to -1.02) mL/min/1.73 m2 lower eGFR as compared with euthyroid subjects (n = 66 542). In (subclinical) hyperthyroid subjects (n = 2254), average eGFR was 3.01 (1.50-4.52) mL/min/1.73 m2 higher. During 329 713 patient years of follow-up, eGFR did not decline more rapidly in individuals with low thyroid function compared with individuals with normal thyroid function. CONCLUSIONS: Low thyroid function is not associated with a deterioration of renal function. The cross-sectional association may be explained by renal dysfunction causing thyroid hormone alterations.

Menopausal hormone therapy and breast cancer risk: effect modification by body mass through life.

It is not known whether increased breast cancer risk caused by menopausal hormone therapy (HT) depends on body mass patterns through life. In a prospective study of 483,241 Norwegian women aged 50-69 years at baseline, 7656 women developed breast cancer during follow-up (2006-2013). We combined baseline information on recalled body mass in childhood/adolescence and current (baseline) body mass index (BMI) to construct mutually exclusive life-course body mass patterns. We assessed associations of current HT use with breast cancer risk according to baseline BMI and life-course patterns of body mass, and estimated relative excess risk due to interaction (RERI). Within all levels of baseline BMI, HT use was associated with increased risk. Considering life-course body mass patterns as a single exposure, we used women who "remained at normal weight" through life as the reference, and found that being "overweight as young" was associated with lower risk (hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.76-0.94), whereas women who "gained weight" had higher risk (HR 1.20, 95% CI 1.12-1.28). Compared to never users of HT who were "overweight as young", HT users who either "remained at normal weight" or "gained weight" in adulthood were at higher risk than expected when adding the separate risks (RERI 0.52, 95% CI 0.09-0.95, and RERI 0.37, 95% CI - 0.07-0.80), suggesting effect modification. Thus, we found that women who remain at normal weight or gain weight in adulthood may be more susceptible to the risk increasing effect of HT compared to women who were overweight as young.

White Blood Cell BRCA1 Promoter Methylation Status and Ovarian Cancer Risk.

Background: The role of normal tissue gene promoter methylation in cancer risk is poorly understood. Objective: To assess associations between normal tissue BRCA1 methylation and ovarian cancer risk. Design: 2 case-control (initial and validation) studies. Setting: 2 hospitals in Norway (patients) and a population-based study (control participants). Participants: 934 patients and 1698 control participants in the initial study; 607 patients and 1984 control participants in the validation study. Measurements: All patients had their blood sampled before chemotherapy. White blood cell (WBC) BRCA1 promoter methylation was determined by using methylation-specific quantitative polymerase chain reaction, and the percentage of methylation-positive samples was compared between population control participants and patients with ovarian cancer, including the subgroup with high-grade serous ovarian cancer (HGSOC). Results: In the initial study, BRCA1 methylation was more frequent in patients with ovarian cancer than control participants (6.4% vs. 4.2%; age-adjusted odds ratio [OR], 1.83 [95% CI, 1.27 to 2.63]). Elevated methylation, however, was restricted to patients with HGSOC (9.6%; OR, 2.91 [CI, 1.85 to 4.56]), in contrast to 5.1% and 4.0% of patients with nonserous and low-grade serous ovarian cancer (LGSOC), respectively. These findings were replicated in the validation study (methylation-positive status in 9.1% of patients with HGSOC vs. 4.3% of control participants-OR, 2.22 [CI 1.40 to 3.52]-4.1% of patients with nonserous ovarian cancer, and 2.7% of those with LGSOC). The results were not influenced by tumor burden, storage time, or WBC subfractions. In separate analyses of young women and newborns, BRCA1 methylation was detected in 4.1% (CI, 1.8% to 6.4%) and 7.0% (CI, 5.0% to 9.1%), respectively. Limitations: Patients with ovarian cancer were recruited at the time of diagnosis in a hospital setting. Conclusion: Constitutively normal tissue BRCA1 promoter methylation is positively associated with risk for HGSOC. Primary Funding Source: Norwegian Cancer Society.

Body mass index, abdominal fatness, weight gain and the risk of psoriasis: a systematic review and dose-response meta-analysis of prospective studies.

Greater body mass index (BMI) has been associated with increased risk of psoriasis in case-control and cross-sectional studies, however, the evidence from prospective studies has been limited. We conducted a systematic review and dose-response meta-analysis of different adiposity measures and the risk of psoriasis to provide a more robust summary of the evidence based on data from prospective studies. PubMed and Embase databases were searched for relevant studies up to August 8th 2017. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a random effects model. The summary relative risk (RR) for a 5 unit increment in BMI was 1.19 (95% CI 1.10-1.28, I2 = 83%, n = 7). The association appeared to be stronger at higher compared to lower levels of BMI, pnonlinearity < 0.0001, and the lowest risk was observed at a BMI around 20. The summary RR was 1.24 (95% CI 1.17-1.31, I2 = 0%, pheterogeneity = 0.72, n = 3) per 10 cm increase in waist circumference, 1.37 (95% CI 1.23-1.53, I2 = 0%, pheterogeneity = 0.93, n = 3) per 0.1 unit increase in waist-to-hip ratio, and 1.11 (95% CI 1.07-1.16, I2 = 47%, pheterogeneity = 0.15, n = 3) per 5 kg of weight gain. Adiposity as measured by BMI, waist circumference, waist-to-hip ratio, and weight gain is associated with increased risk of psoriasis.

Body Mass Index, Abdominal Fatness, and Heart Failure Incidence and Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies.

BACKGROUND: Obesity has been associated with increased risk of heart failure, but whether overweight also increases risk is unclear. It is also unclear whether abdominal adiposity is more strongly associated with heart failure risk than general adiposity. We conducted a systematic review and meta-analysis of prospective studies to clarify the strength and shape of the dose-response relationship between general and abdominal adiposity and the risk of heart failure. METHODS AND RESULTS: PubMed and Embase databases were searched up to October 10, 2014. Summary relative risks were calculated using random-effects models. A total of 28 studies (27 publications) were included. Twenty-three prospective studies with >15 905 incident cases among 647 388 participants were included in the analysis of body mass index and heart failure incidence, and 4 studies were included for heart failure mortality. The summary relative risk for a 5-unit increment in body mass index was 1.41 (95% confidence interval, 1.34-1.47; I(2)=83%) for heart failure incidence and 1.26 (95% confidence interval, 0.85-1.87; I(2)=95%) heart failure mortality. Although the test for nonlinearity was significant (P<0.0001), this appeared to be attributable to a threshold at a body mass index of ≈23 to 24 kg/m(2); however, there was evidence of increased risk even in the overweight body mass index range. The summary relative risk for a 10-cm increase in waist circumference was 1.29 (95% confidence interval, 1.21-1.37; I(2)=89%) and per 0.1-unit increase in waist-to-hip ratio was 1.29 (95% confidence interval, 1.13-1.47; I(2)=82%). CONCLUSION: Overweight and obesity and abdominal adiposity are associated with increased risk of heart failure.

Body mass index, abdominal fatness, fat mass and the risk of atrial fibrillation: a systematic review and dose-response meta-analysis of prospective studies.

Different adiposity measures have been associated with increased risk of atrial fibrillation, however, results have previously only been summarized for BMI. We therefore conducted a systematic review and meta-analysis of prospective studies to clarify the association between different adiposity measures and risk of atrial fibrillation. PubMed and Embase databases were searched up to October 24th 2016. Summary relative risks (RRs) were calculated using random effects models. Twenty-nine unique prospective studies (32 publications) were included. Twenty-five studies (83,006 cases, 2,405,381 participants) were included in the analysis of BMI and atrial fibrillation. The summary RR was 1.28 (95% confidence interval: 1.20-1.38, I2 = 97%) per 5 unit increment in BMI, 1.18 (95% CI: 1.12-1.25, I2 = 73%, n = 5) and 1.32 (95% CI: 1.16-1.51, I2 = 91%, n = 3) per 10 cm increase in waist and hip circumference, respectively, 1.09 (95% CI: 1.02-1.16, I2 = 44%, n = 4) per 0.1 unit increase in waist-to-hip ratio, 1.09 (95% CI: 1.02-1.16, I2 = 94%, n = 4) per 5 kg increase in fat mass, 1.10 (95% CI: 0.92-1.33, I2 = 90%, n = 3) per 10% increase in fat percentage, 1.10 (95% CI: 1.08-1.13, I2 = 74%, n = 10) per 5 kg increase in weight, and 1.08 (95% CI: 0.97-1.19, I2 = 86%, n = 2) per 5% increase in weight gain. The association between BMI and atrial fibrillation was nonlinear, p nonlinearity < 0.0001, with a stronger association at higher BMI levels, however, increased risk was observed even at a BMI of 22-24 compared to 20. In conclusion, general and abdominal adiposity and higher body fat mass increase the risk of atrial fibrillation.

Body mass index and physical activity and the risk of diverticular disease: a systematic review and meta-analysis of prospective studies.

PURPOSE: We conducted a systematic review and meta-analysis of prospective studies of the association between body mass index (BMI) and physical activity and diverticular disease risk. METHODS: PubMed and Embase databases were searched up to February 7, 2017. Summary relative risks and 95% confidence intervals (95% CIs) were calculated using a random effects model and nonlinear associations were modeled using fractional polynomial models. RESULTS: Six cohort studies of BMI and diverticular disease risk (28,915 cases, 1,636,777 participants) and five cohort studies of physical activity and diverticular disease risk (2080 cases, 147,869 participants) were included. The summary relative risk (RR) of incident diverticular disease for a 5 unit BMI increment was 1.28 (95% CI: 1.18-1.40, I 2 = 77%, n = 6) for diverticular disease, 1.31 (95% CI: 1.09-1.56, I 2 = 74%, n = 2) for diverticulitis, and 1.20 (95% CI: 1.04-1.40, I 2 = 56%, n = 3) for diverticular disease complications. There was no evidence of a nonlinear association between BMI and diverticular disease risk (p nonlinearity = 0.22), and risk increased even within the normal weight range. Compared to a BMI of 20, the summary RR for a BMI of 22.5, 25.0, 27.5, 30.0, 32.5, 35.0, 37.5, and 40.0 was 1.15 (1.07-1.23), 1.31 (1.17-1.47), 1.50 (1.31-1.71), 1.71 (1.52-1.94), 1.96 (1.77-2.18), 2.26 (2.00-2.54), 2.60 (2.11-3.21), and 3.01 (2.06-4.39), respectively. The summary RR was 0.76 (95% CI: 0.63-0.93, I 2 = 54%, n = 5) for high vs. low physical activity and 0.74 (95% CI: 0.57-0.97, I 2 = 39.5%, p heterogeneity = 0.20, n = 2) for high vs. low vigorous physical activity. CONCLUSIONS: These results suggest that even moderate increases in BMI may increase the risk of diverticular disease as well as diverticular disease complications and that a higher level of physical activity may reduce the risk.

Nut consumption and risk of cardiovascular disease, total cancer, all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective studies.

BACKGROUND: Although nut consumption has been associated with a reduced risk of cardiovascular disease and all-cause mortality, data on less common causes of death has not been systematically assessed. Previous reviews missed several studies and additional studies have since been published. We therefore conducted a systematic review and meta-analysis of nut consumption and risk of cardiovascular disease, total cancer, and all-cause and cause-specific mortality. METHODS: PubMed and Embase were searched for prospective studies of nut consumption and risk of cardiovascular disease, total cancer, and all-cause and cause-specific mortality in adult populations published up to July 19, 2016. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random-effects models. The burden of mortality attributable to low nut consumption was calculated for selected regions. RESULTS: Twenty studies (29 publications) were included in the meta-analysis. The summary RRs per 28 grams/day increase in nut intake was for coronary heart disease, 0.71 (95% CI: 0.63-0.80, I2 = 47%, n = 11), stroke, 0.93 (95% CI: 0.83-1.05, I2 = 14%, n = 11), cardiovascular disease, 0.79 (95% CI: 0.70-0.88, I2 = 60%, n = 12), total cancer, 0.85 (95% CI: 0.76-0.94, I2 = 42%, n = 8), all-cause mortality, 0.78 (95% CI: 0.72-0.84, I2 = 66%, n = 15), and for mortality from respiratory disease, 0.48 (95% CI: 0.26-0.89, I2 = 61%, n = 3), diabetes, 0.61 (95% CI: 0.43-0.88, I2 = 0%, n = 4), neurodegenerative disease, 0.65 (95% CI: 0.40-1.08, I2 = 5.9%, n = 3), infectious disease, 0.25 (95% CI: 0.07-0.85, I2 = 54%, n = 2), and kidney disease, 0.27 (95% CI: 0.04-1.91, I2 = 61%, n = 2). The results were similar for tree nuts and peanuts. If the associations are causal, an estimated 4.4 million premature deaths in the America, Europe, Southeast Asia, and Western Pacific would be attributable to a nut intake below 20 grams per day in 2013. CONCLUSIONS: Higher nut intake is associated with reduced risk of cardiovascular disease, total cancer and all-cause mortality, and mortality from respiratory disease, diabetes, and infections.

Short-Term Public Health Impact of the July 22, 2011, Terrorist Attacks in Norway: A Nationwide Register-Based Study.

OBJECTIVES: To examine increases in several health outcomes after the July 22, 2011 terrorist attacks in Norway. METHODS: Retrospective analysis of nationwide registers (n = 4,953,000) where incidences of schizophrenia/psychosis hospitalizations, suicides, acute myocardial infarctions, and preterm births after the terrorist attacks were compared with corresponding periods the previous 3 years. RESULTS: Compared with the same period the preceding 3 years, the observed number of hospitalizations from schizophrenia/psychosis was 14% higher during the first 4 weeks after the terrorist attack (incidence ratio [IR] = 1.14, 95% confidence interval [CI] = 1.07-1.21). The corresponding IRs for the first 3 days and the first week were 1.26 (95% CI = 0.99-1.58) and 1.10 (95% CI = 0.96-1.24). The observed number of suicides was increased by 45% the first 4 weeks (IR = 1.45, 95% CI = 1.12-1.86), 163% the first 3 days (IR = 2.63, 95% CI = 1.15-5.20), and 105% the first week (IR = 2.05, 95% CI = 1.14-3.42). For acute myocardial infarction, there was an increase of 5% the first 4 weeks. There were also more births the 4 weeks (IR = 1.04, 95% CI = 1.01-1.07, but this increase was not seen in preterm births of less than 37 weeks of gestation (IR = 0.93, 95% CI = 0.83-1.04). CONCLUSIONS: We observed a general nationwide increase of health outcomes investigated in this study the first 4 weeks after the terrorist attacks. These results may contribute to the growing body of evidence on the adverse health outcomes that may accompany national stressors.

Tobacco smoking and the risk of gallbladder disease.

Tobacco smoking has been inconsistently associated with gallbladder disease risk. To clarify the association we conducted a systematic review and meta-analysis of cohort studies published on the subject. We searched the PubMed and Embase databases for studies of smoking and gallbladder disease up to January 9th 2015. Prospective studies were included if they reported relative risk estimates and 95 % confidence intervals of gallbladder disease associated with current, former or ever smoking and by number of cigarettes per day. Summary relative risks were estimated by use of a random effects model. We identified ten prospective studies including 59,530 gallbladder disease cases among 4,213,482 participants that could be included in the meta-analysis. The summary RR was 1.19 (95 % CI 1.12-1.28, I(2) = 46.9 %, n = 6) for current smokers, 1.10 (95 % CI 1.07-1.13, I(2) = 0 %, n = 6) for former smokers and 1.15 (95 % CI 1.13-1.18, I(2) = 0 %, n = 7) for ever smokers. In the dose-response analysis the summary relative risk was 1.11 (95 % CI 1.08-1.14, I(2) = 33 %, n = 3) per 10 cigarettes per day and although there was indication of nonlinearity there was a dose-dependent positive association with increasing number of cigarettes smoked per day. The current meta-analysis provides evidence of an increased risk of gallbladder disease associated with tobacco smoking.

Preeclampsia in pregnancies with and without diabetes: the associations with placental weight. A population study of 655 842 pregnancies.

INTRODUCTION: Women with diabetes are at increased risk of preeclampsia, and women with diabetes tend to deliver placentas and offspring that are large-for-gestational-age. We therefore studied placental weight in preeclamptic pregnancies according to maternal diabetes status. MATERIAL AND METHODS: Information on all singleton births from 1999 through 2010 (n = 655 842) were obtained from the Medical Birth Registry of Norway. We used z-scores of placental weight to adjust for differences in gestational age at birth between deliveries, and compared the distribution of placental weight z-scores, in deciles, in preeclamptic pregnancies with and without diabetes, and in non-preeclamptic pregnancies with and without diabetes. RESULTS: Overall, the prevalence of preeclampsia was higher in pregnancies with diabetes than in pregnancies without diabetes (9.9% vs. 3.6%). Among preeclamptic pregnancies, having a placental weight in the highest decile was nearly three times more frequent (28.8%) in pregnancies with diabetes than in pregnancies without diabetes (9.8%). In the lowest decile, preeclamptic pregnancies with diabetes were underrepresented (7.5%), and preeclamptic pregnancies without diabetes were overrepresented (13.6%). Among pregnancies with preterm delivery, the above patterns were more pronounced, with 30.1% of the placentas in in preeclamptic pregnancies with diabetes in the highest decile, and 19.5% of the placentas in preeclamptic pregnancies without diabetes in the lowest decile. CONCLUSIONS: These results suggest that women with diabetes who develop preeclampsia have a higher placental weight than other women with preeclampsia or non-preeclamptic women.

Invasive lobular breast cancer: the prognostic impact of histopathological grade, E-cadherin and molecular subtypes.

AIMS: The aim of this study was to compare breast cancer specific survival (BCSS) for invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) and, further, to evaluate critically the prognostic value of histopathological grading of ILC and examine E-cadherin as a prognostic marker in ILC. METHODS AND RESULTS: The study comprised 116 lobular and 611 ductal breast carcinomas occurring between 1961 and 2008. All cases had been classified previously according to histopathological type and grade, stained for oestrogen receptor (ER), progesterone receptor (PR), antigen Ki67 (Ki67), epithelial growth factor receptor (EGFR), cytokeratin 5 (CK5) and human epidermal growth factor receptor 2 (HER2) and classified into molecular subtypes. For the present study, immunohistochemical staining for E-cadherin was performed. The Kaplan-Meier method and Cox proportional hazards models were used in the analyses. Grade 2 tumours comprised 85.3% of the lobular tumours and 51.9% of the ductal tumours. BCSS in ILC grade 2 was comparable to that of IDC grade 3. E-cadherin-negative ILC had a poorer prognosis compared to E-cadherin positive ILC and to IDC regardless of E-cadherin status. CONCLUSIONS: The implication of histopathological grading may differ in ILC compared to IDC. E-cadherin may be useful in prognostication in ILC and thereby influence the determination of treatment strategies for this group of women.

Body mass index, abdominal fatness and the risk of gallbladder disease.

Epidemiological studies have indicated a positive association between adiposity and gallbladder disease risk, however, the shape of the dose-response relationship and differences between overall and abdominal adiposity remains to be clarified. We conducted a systematic review and dose-response meta-analysis of cohort studies of body mass index (BMI), waist circumference and waist-to-hip ratio and risk of gallbladder disease. PubMed and Embase databases were searched up to January 9th 2015. Summary relative risks were calculated using a random effects model. Seventeen prospective studies of BMI and gallbladder disease risk with 55,670 cases among 1,921,103 participants were included. The summary relative risk (RR) for a 5 unit increment in BMI was 1.63 (95 % CI 1.49-1.78, I(2) = 98 %). There was evidence of a nonlinear association overall and among women, p(nonlinearity) < 0.0001, but not among men, p(nonlinearity) = 0.99, with a slight flattening of the curve at very high BMI levels (BMI 40-45), however, the risk of gallbladder disease increased almost twofold even within the "normal" BMI range. The summary RR for a 10 cm increase in waist circumference was 1.46 (95 % CI 1.24-1.72, I(2) = 98 %, n = 5) and for a 0.1 unit increment in waist-to-hip ratio was 1.44 (95 % CI 1.26-1.64, I(2) = 92 %, n = 4). Associations were attenuated, but still significant, when BMI and abdominal adiposity measures were mutually adjusted. Our results confirm a positive association between both general and abdominal fatness and the risk of gallbladder disease. There is an almost twofold increase in the risk even within the "normal" BMI range, suggesting that even moderate increases in BMI may increase risk.

Insomnia and the risk of incident heart failure: a population study.

AIMS: Insomnia is highly prevalent among heart failure patients, but only a few small studies have investigated insomnia symptoms and risk of heart failure. We aimed to assess the prospective association between self-reported insomnia symptoms and the risk of incident heart failure in a large Norwegian cohort. METHODS AND RESULTS: Baseline data on insomnia symptoms, including difficulty initiating sleep, difficulty maintaining sleep and having non-restorative sleep, socio-demographic variables, and health status, including established cardiovascular risk factors, were collected from 54 279 men and women 20-89 years of age who participated in the Nord-Trøndelag Health study (HUNT) between 1995 and 1997 and were free from known heart failure at baseline. The cohort was followed for incident heart failure from baseline through 2008. We used Cox proportional hazard models to assess the association of baseline insomnia symptoms with the risk of heart failure. A total of 1412 cases of heart failure occurred during a mean follow-up of 11.3 years (SD = 2.9 years), either identified at hospitals or by the National Cause of Death Registry. There was a dose-dependent association between the number of insomnia symptoms and risk of heart failure. The multi-adjusted hazard ratios were 0.96 (0.57-1.61), 1.35 (0.72-2.50), and 4.53 (1.99-10.31) for people with one, two, and three insomnia symptoms, compared with people with none of the symptoms (P for trend 0.021). CONCLUSIONS: Insomnia is associated with an increased risk of incident heart failure. If our results are confirmed by others and causation is proved, evaluation of insomnia symptoms might have consequences for cardiovascular prevention.

Anthropometric factors and risk of molecular breast cancer subtypes among postmenopausal Norwegian women.

Adult height and body weight are positively associated with breast cancer risk after menopause, but few studies have investigated these factors according to molecular breast cancer subtype. A total of 18,562 postmenopausal Norwegian women who were born between 1886 and 1928 were followed up for breast cancer incidence from the time (between 1963 and 1975) height and weight were measured until 2008. Immunohistochemical and in situ hybridization techniques were used to subtype 734 incident breast cancer cases into Luminal A, Luminal B [human epidermal growth factor receptor 2 (HER2-)], Luminal B (HER2+), HER2 subtype, basal-like phenotype (BP) and five-negative phenotype (5NP). We used Cox regression analysis to assess adult height and body mass index (BMI) in relation to risk of these subtypes. We found a positive association of height with risk of Luminal A breast cancer (ptrend , 0.004), but there was no clear association of height with any other subtype. BMI was positively associated with risk of all luminal breast cancer subtypes, including Luminal A (ptrend , 0.002), Luminal B (HER2-) (ptrend , 0.02), Luminal B (HER2+) (ptrend , 0.06), and also for the HER2 subtype (ptrend , 0.04), but BMI was not associated with risk of the BP or 5NP subtypes. Nonetheless, statistical tests for heterogeneity did not provide evidence that associations of height and BMI differed across breast cancer subtypes. This study of breast cancer risk among postmenopausal women suggests that height is positively associated with risk of Luminal A breast cancer. BMI is positively associated with risk of all luminal subtypes and for the HER2 subtype.

Reproductive history and the risk of molecular breast cancer subtypes in a prospective study of Norwegian women.

PURPOSE: Breast cancer can be classified into molecular subtypes that differ in clinical characteristics and prognosis. There is some but conflicting evidence that reproductive risk factors may differ between distinct breast cancer subtypes. METHODS: We investigated associations of reproductive factors with the risk for six molecular breast cancer subtypes in a cohort of 21,532 Norwegian women who were born between 1886 and 1928 and followed up for breast cancer incidence between 1961 and 2008. We obtained stored tumor tissue from incident breast cancers and used immunohistochemistry and in situ hybridization to classify 825 invasive tumors into three luminal subtypes [Luminal A, Luminal B (HER2-) and Luminal B (HER2+)] and three non-luminal subtypes [human epidermal growth factor receptor 2 (HER2) subtype, basal-like phenotype (BP) and five negative phenotype (5NP)]. We used Cox regression to assess reproductive factors and risk for each subtype. RESULTS: We found that young age at menarche, old age at first birth and low parity were associated with increased risk for luminal breast cancer subtypes. For the HER2 subtype, we either found no association or associations in the opposite direction compared to the luminal subtypes. The BP subtype appeared to have a similar reproductive risk profile as the luminal subtypes. Breastfeeding was associated with a reduced risk for HER2 and 5NP subtypes, but was not associated with any other subtype. CONCLUSIONS: The results suggest that molecular breast cancer subtypes differ in their reproductive risk factors, but associations with non-luminal subtypes are still poorly understood and warrant further study.

A population-based study of associations between preeclampsia and later cardiovascular risk factors.

OBJECTIVE: Women with a history of preeclampsia are at increased lifetime risk for cardiovascular disease. Their offspring may carry similar risks. The aim was to study cardiovascular and metabolic risk factors 11 years after the delivery among women who were diagnosed with mild, moderate, or severe preeclampsia, and their offspring, compared with women without preeclampsia and their offspring. STUDY DESIGN: In a follow-up 11 years after a nested case-control study at birth, we studied 611 mother-offspring dyads, including 228 dyads with preeclampsia in the index pregnancy and 383 dyads without preeclampsia. Cardiovascular and metabolic risk profiles were assessed by serum lipids (total cholesterol, high-density lipoprotein [HDL] cholesterol, non-HDL cholesterol), insulin-related factors (glucose, insulin, and homeostasis assessment model for insulin resistance) and blood pressure in mothers and children. RESULTS: Among mothers with mild or moderate preeclampsia, levels of glucose, insulin, and homeostasis assessment model for insulin resistance were higher than in the nonpreeclampsia group and also higher compared with mothers with severe preeclampsia (all P < .05). HDL cholesterol was lower in mothers with mild or moderate preeclampsia (all P < .05), but other lipids did not substantially differ between the groups. Body mass index and blood pressure (systolic and diastolic) were also higher in the mild and moderate preeclampsia group compared with mothers without preeclampsia (all P < .05). Among the offspring, we found no clear differences in any blood analytes between the groups. CONCLUSION: Women with a previous diagnosis of mild or moderate, but not severe, preeclampsia may have an adverse metabolic and cardiovascular risk profile 11 years after the delivery.

Maternal and cord blood hormones in relation to birth size.

Birth size has been associated with adult life diseases, but the endocrine factors that are likely involved are not established. We evaluated the associations of maternal and cord blood hormones with birth size in normal pregnancies, and examined possible effect modification by maternal height, on the basis of prior suggestive evidence. In a prospective study of normal singleton pregnancies in Boston, USA and Shanghai, China, maternal hormone levels at the 27th gestational week were available for 225 pregnancies in Boston and 281 in Shanghai and cord blood measurements for 92 pregnancies in Boston and 110 in Shanghai. Pearson partial correlation coefficients of log-transformed hormone levels with birth weight and length were calculated. Overall, positive correlations with birth weight were found for maternal estriol (r = 0.19; p < 0.001) and progesterone (r = 0.15; p < 0.001) and these associations were more evident among taller mothers. There was an inverse association of cord blood progesterone (r = -0.16; p < 0.03) with birth weight. In Boston, cord blood IGF-1 was positively associated with birth weight (r = 0.22; p < 0.04) and length (r = 0.25; p < 0.02), particularly among taller mothers (r = 0.43 and 0.38, respectively; p < 0.02), whereas among taller mothers in Shanghai the associations of IGF-2 with birth size appeared to be at least as strong as those of IGF-1. In conclusion, maternal estriol and progesterone, and cord blood IGF-1 were positively correlated with birth size. All correlations tended to be more pronounced among offspring of taller mothers. Among taller mothers in Shanghai, IGF-2 appeared to be at least as strongly associated with birth size as IGF-1.