Confounded association between proton pump inhibitor use and risk of biliary tract cancer: Result from three cohorts

Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes.

Sexual Violence and Risk of Hypertension in Women in the Nurses' Health Study II: A 7-Year Prospective Analysis

Background Hypertension is a prevalent condition in women and an important modifiable risk factor for cardiovascular disease. Despite women's experiences of sexual violence being common, no prospective studies have examined lifetime sexual assault and workplace sexual harassment in relationship to hypertension in large civilian samples with extended follow-up. Here, we examined whether these experiences were prospectively associated with greater risk of developing hypertension over 7 years. Methods and Results Data are from a substudy of the Nurses' Health Study II and include women free of hypertension at the time of sexual assault and workplace sexual harassment assessment in 2008 (n=33 127). Hypertension was defined as self-reported doctor diagnosis or initiating antihypertensive medication use, assessed biennially through 2015. We performed Cox proportional hazards regression models to predict time to developing hypertension associated with sexual violence exposure, adjusting for relevant covariates. Over follow-up, 7096 women developed hypertension. Sexual assault and workplace sexual harassment were prevalent (23% and 12%, respectively; 6% of women experienced both). Compared with women with no exposure, women who experienced both sexual assault and workplace sexual harassment had the highest risk of developing hypertension (hazard ratio [HR], 1.21; 95% CI, 1.09-1.35), followed by women who experienced workplace sexual harassment (HR, 1.15; 95% CI, 1.05-1.25) and then by women who experienced sexual assault (HR, 1.11; 95% CI, 1.03-1.19), after adjusting for relevant covariates. Conclusions Sexual assault and workplace sexual harassment are prospectively associated with greater risk of hypertension. Reducing such violence is important in its own right and may also improve women's cardiovascular health.

Prepregnancy handling of antineoplastic drugs and risk of miscarriage in female nurses

PURPOSE

To examine the association betweenantineoplastic drug (AD) handling and risk of miscarriage.

METHODS

Nurses' Health Study-3 participants self-reported AD administration and engineering controls (ECs) and personal protective equipment (PPE) use at baseline. We estimated the hazard ratio (HR) of miscarriage in relation to baseline AD handling using multivariable Cox proportional regression.

RESULTS

Overall, 2440 nurses reported 3327 pregnancies, with 550 (17%) ended in miscarriages. Twelve percent of nurses self-reported currently handling AD and 28% previously handling AD. Compared with nurses who never handled AD, nurses who handled AD at baseline had an adjusted HR of miscarriage of 1.26 (95% confidence interval [CI], 0.97-1.64). This association was stronger after 12-weeks gestation (HR=2.39 [95% CI, 1.13-5.07]). Nurses who did not always use gloves had HR of 1.51 (95% CI, 0.91-2.51) compared with 1.19 (95% CI, 0.89-1.60) for those always using gloves; nurses who did not always use gowns had HR of 1.32 (95% CI, 0.95-1.83) compared with 1.19 (95% CI, 0.81-1.75) for nurses always using gowns.

CONCLUSIONS

We observed a suggestive association between AD handling and miscarriage, particularly among nurses who did not consistently use PPE and EC with stronger associations for second trimester losses.

Anti-Müllerian hormone levels in nurses working night shifts

Our objective was to examine associations between night shift work and serum anti-Müllerian hormone (AMH) levels. We analyzed 1,537 blood samples from premenopausal female nurses in the Nurses' Health Study II, assayed for AMH. Rotating or permanent night shifts worked in the two weeks before blood collection and years of rotating night shift work were obtained via questionnaire. We found no associations between recent night shifts or rotating night shift work and AMH. The median difference in AMH was 0.3 (95% CI: -0.4, 0.8) ng/mL for ≥5 versus 0 recent night shifts and -0.1 (95% CI: -0.4, 0.3) ng/mL for ≥6 versus 0 years of rotating night shift work. Although we found no associations between night shift work and AMH, this does not preclude associations between night shift work and fertility operating through other mechanisms.

Medicare Utilization and Spending Among Nurses Compared with the General United States Population

Background: To better understand health habits in older nurses versus the general population, we sought to determine whether the demographics, health care utilization, and Medicare spending by the Nurses' Health Study (NHS) participants enrolled in Medicare and a matched sample of Medicare beneficiaries meaningfully differed. Materials and Methods: Analytic cohorts included a random 20% sample of Medicare beneficiaries continuously enrolled in fee for service (FFS) Medicare that were propensity matched to the NHS participants continuously enrolled in FFS Medicare in a single year (2012). Matching was based upon preselected demographic factors and health status, using a nearest-neighbor matching algorithm to obtain a 1:1 match without replacement. Healthcare utilization and spending were compared between the two groups; we also stratified findings by number of chronic comorbidities. Results: Similar rates of utilization of primary care and most outpatient services. However, NHS participants had slightly higher rates of cancer screening, specialist care, and inpatient surgery were observed. When stratified by comorbidity status, the largest differences in utilization and spending were found in women with no comorbidity. Conclusions: The modest differences in observed healthcare utilization and spending suggest that older healthcare professionals may access care in fairly similar ways to the general population, and that health status may be a more important determinant of utilization and spending than health profession in older age groups.

Diuretic Use and Risk of Vertebral Fracture in Women

BACKGROUND

Vertebral fracture is the most common type of osteoporotic fracture. While thiazide diuretics, which are commonly prescribed for the treatment of hypertension, decrease calciuria, they may also induce hyponatremia, which has been associated with increased vertebral fracture risk. Loop diuretics increase calciuria, which would reduce bone mineral density and increase vertebral fracture risk, but they rarely cause hyponatremia. Recent studies on diuretics and fractures did not include or specifically examine vertebral fracture. The few studies of diuretics and vertebral fracture have been limited by cases defined by self-report or administrative data, relatively small number of cases, study design that was not prospective, and lack of long-term follow-up with updated information on diuretic use.

METHODS

We conducted a prospective cohort study of thiazide diuretic use, loop diuretic use, and risk of incident clinical vertebral fracture in 55,780 women, 55-82 years of age, participating in the Nurses' Health Study, without a prior history of any fracture. Diuretic use was assessed by questionnaire every 4 years. Self-reported vertebral fracture was confirmed by medical record review. Cox proportional-hazards models were used to simultaneously adjust for potential confounders.

RESULTS

Our analysis included 420 incident vertebral fracture cases documented between 2002 and 2012. The multivariate-adjusted relative risk of clinical vertebral fracture for women taking thiazides compared with women not taking thiazides was 1.47 (95% confidence interval, 1.18-1.85). The multivariate adjusted relative risk of vertebral fracture for women taking loop diuretics compared with women not taking loop diuretics was 1.59 (95% confidence interval, 1.12-2.25).

CONCLUSION

Thiazide diuretics and loop diuretics are each independently associated with increased risk of vertebral fracture in women.

Longitudinal and secular trends in dietary supplement use: Nurses' Health Study and Health Professionals Follow-Up Study, 1986-2006

Most studies on the prevalence of supplement use in the United States were cross-sectional or evaluated trends in limited variety of supplements. The objective of this study was to describe the longitudinal and secular trend of dietary supplement use over the past 20 years in health professionals using data from two large prospective cohorts. We analyzed cohort data from 1986 to 2006 in the Nurses' Health Study (NHS) and the Health Professionals Follow-Up Study (HPFS). In 1986, 74,194 women aged 40 to 65 years in the NHS and 50,497 men aged 40 to 75 years in the HPFS were included. Use of dietary supplements including multivitamins, vitamins, and minerals was repeatedly asked every 4 years. Generalized estimating equation models were used for repeated analysis. Prevalence of use of any supplement increased among both women (71.3% to 88.3%) and men (56.4% to 80.7%) from 1986 to 2006. Notably, longitudinal increases in the prevalence of use of vitamin D (2.2% to 32.2% for women and 1.1% to 6.7% for men), folic acid (0.8% to 10.7% for women and 1.1% to 13.8% for men), and fish oil (1.6% to 18.1% for women and 3.3% to 22.2% for men) supplements were observed from 1990 to 2006. However, the use of vitamin A, beta carotene, vitamin C, and vitamin E supplements peaked in 1994 or 1998, then declined steadily. A secular increase in use of multivitamins, vitamin D, folic acid, and fish oil across same age group was noted. In conclusion, the use of many types of dietary supplements has increased over time, but the use of antioxidant supplements has declined. The secular increase in the prevalence of use of supplements across the same age group suggests that aging of the population is not the primary reason for the increase. These findings in health professionals need to be replicated in the general populations.

A prospective study of long-term intake of dietary fiber and risk of Crohn's disease and ulcerative colitis

BACKGROUND & AIMS

Increased intake of dietary fiber has been proposed to reduce the risk of inflammatory bowel disease (Crohn's disease [CD] and ulcerative colitis [UC]). However, few prospective studies have examined associations between long-term intake of dietary fiber and risk of incident CD or UC.

METHODS

We collected and analyzed data from 170,776 women, followed up over 26 years, who participated in the Nurses' Health Study, followed up for 3,317,425 person-years. Dietary information was prospectively ascertained via administration of a validated semiquantitative food frequency questionnaire every 4 years. Self-reported CD and UC were confirmed through review of medical records. Cox proportional hazards models, adjusting for potential confounders, were used to calculate hazard ratios (HRs).

RESULTS

We confirmed 269 incident cases of CD (incidence, 8/100,000 person-years) and 338 cases of UC (incidence, 10/100,000 person-years). Compared with the lowest quintile of energy-adjusted cumulative average intake of dietary fiber, intake of the highest quintile (median of 24.3 g/day) was associated with a 40% reduction in risk of CD (multivariate HR for CD, 0.59; 95% confidence interval, 0.39-0.90). This apparent reduction appeared to be greatest for fiber derived from fruits; fiber from cereals, whole grains, or legumes did not modify risk. In contrast, neither total intake of dietary fiber (multivariate HR, 0.82; 95% confidence interval, 0.58-1.17) nor intake of fiber from specific sources appeared to be significantly associated with risk of UC.

CONCLUSIONS

Based on data from the Nurses' Health Study, long-term intake of dietary fiber, particularly from fruit, is associated with lower risk of CD but not UC. Further studies are needed to determine the mechanisms that mediate this association.

Oral contraceptives, reproductive factors and risk of inflammatory bowel disease

BACKGROUND

Oral contraceptive use has been associated with risk of Crohn's disease (CD) and ulcerative colitis (UC).

OBJECTIVE

To determine whether this association is confounded or modified by other important lifestyle and reproductive factors.

DESIGN

A prospective cohort study was carried out of 117,375 US women enrolled since 1976 in the Nurses Health Study I (NHS I) and 115,077 women enrolled since 1989 in the Nurses' Health Study II (NHS II) with no prior history of UC or CD. These women had provided information every 2 years, on age at menarche, oral contraceptive use, parity, menopause status and other risk factors. Diagnoses of CD and UC were confirmed by review of medical records. Cox proportional hazards models were used to calculate HRs and 95% CIs.

RESULTS

Among 232,452 women with over 5,030,196 person-years of follow-up, 315 cases of CD and 392 cases of UC were recorded through 2007 in NHS II and 2008 in NHS I. Compared with never users of oral contraceptives, the multivariate-adjusted HRs for CD were 2.82 (95% CI 1.65 to 4.82) among current users and 1.39 (95% CI 1.05 to 1.85) among past users. The association between oral contraceptives and UC differed according to smoking history (pheterogeneity=0.04). Age at menarche, age at first birth and parity were not associated with risk of UC or CD.

CONCLUSION

In two large prospective cohorts of US women, oral contraceptive use was associated with risk of CD. The association between oral contraceptive use and UC was limited to women with a history of smoking.

Isotemporal substitution analysis for physical activity, television watching, and risk of depression

The isotemporal substitution model (ISM) was previously developed as a methodology to study the time-substitution effects of 1 type of activity for another in a data setting with continuous outcomes. To demonstrate the application of ISM with a dichotomous outcome, we prospectively examined the associations of different activities with various activity displacements with depression risk among 32,900 US women from the Nurses' Health Study who were free from depressive symptoms at baseline (in 1996). During a 10-year follow-up, 5,730 incident depression cases were documented. Results from the ISMs indicated that for each physical activity, differences in magnitude of effects of each activity type were observed, dependent on the activity being displaced/substituted. Notably, an isotemporal substitution gradient was found for television watching, in which its association with depression risk varied by its substitution for slow-, average-, or brisk-paced walking in a gradient toward high depression risk when television watching replaced a faster walking pace (relative risk = 1.18, 95% confidence interval: 1.05, 1.31). Conversely, no association with depression was found for replacement of television watching with 60 minutes/day of slow walking, whereas a lower depression risk (relative risk = 0.85, 95% confidence interval: 0.76, 0.95) was found when 60 minutes/day of brisk walking replaced 60 minutes/day of television watching. Thus, the ISM could offer a more meaningful alternative to the standard nonsubstitution models to support public health recommendations.