Risk of urolithiasis associated with allopurinol versus benzbromarone among patients with gout: a population-based cohort study

OBJECTIVES

To compare the risk of urolithiasis in gout patients initiating allopurinol, a xanthine oxidase inhibitor, vs benzbromarone, a uricosuric.

METHODS

Using the 2011-2020 Korea National Health Insurance Service database, we conducted a cohort study on gout patients initiating allopurinol vs benzbromarone as the 1st-line urate-lowering treatment (ULT). The primary outcome was a new onset urinary stone. The secondary outcome was a stone requiring intervention. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazard models with a 5:1 ratio propensity-score matching on > 80 variables. Subgroup analyses were done by age, sex, thiazide use, and cardiovascular (CV) risk.

RESULTS

61 300 allopurinol initiators PS-matched on 12 260 benzbromarone initiators were included (mean age 59 years, 79% male). During a mean follow-up of 322 days, 619 urolithiasis cases occurred with an incidence rate of 0.87 per 100 person-years in allopurinol and 1.39 in benzbromarone initiators, showing a HR of 0.64 (95% CI, 0.51-0.80). ∼44% of urinary stones required intervention with a HR of 0.61 (95% CI 0.43-0.88). The lower risk associated with allopurinol compared with benzbromarone persisted across subgroups but was greater in the high than non-high CV risk subgroup (p for interaction = 0.02).

CONCLUSION

This population-based cohort study found that allopurinol compared with benzbromarone was associated with a substantially lower risk of urolithiasis particularly in the presence of the high CV risk. This finding provides important safety information for clinicians' decision-making on ULTs of different mechanisms of action.

Hypothesis Tests for Continuous Audiometric Threshold Data

OBJECTIVES

Hypothesis tests for hearing threshold data may be challenging due to the special structure of the response variable, which consists of the measurements from the participant's two ears at multiple frequencies. The commonly-used methods may have inflated type I error rates for the global test that examines whether exposure-hearing threshold associations exist in at least one of the frequencies. We propose using both-ear methods, including all frequencies in the same model for hypothesis testing.

DESIGN

We compared the both-ear method to commonly used single-ear methods, such as the worse-ear, better-ear, left/right-ear, average-ear methods, and both-ear methods that evaluate individual audiometric frequencies in separate models, through both theoretical consideration and a simulation study. Differences between the methods were illustrated using hypothesis tests for the associations between the Dietary Approaches to Stop Hypertension adherence score and 3-year change in hearing thresholds among participants in the Conservation of Hearing Study.

RESULTS

We found that (1) in the absence of ear-level confounders, the better-ear, worse-ear and left/right-ear methods have less power for frequency-specific tests and for the global test; (2) in the presence of ear-level confounders, the better-ear and worse-ear methods are invalid, and the left/right-ear and average-ear methods have less power, with the power loss in the left/right-ear much greater than the average-ear method, for frequency-specific tests and for the global test; and (3) the both-ear method with separate analyses for individual frequencies is invalid for the global test.

CONCLUSIONS

For hypothesis testing to evaluate whether there are significant associations between an exposure of interest and audiometric hearing threshold measurements, the both-ear method that includes all frequencies in the same model is the recommended analytic approach.

Soft classification and regression analysis of audiometric phenotypes of age-related hearing loss

Age-related hearing loss has a complex etiology. Researchers have made efforts to classify relevant audiometric phenotypes, aiming to enhance medical interventions and improve hearing health. We leveraged existing pattern analyses of age-related hearing loss and implemented the phenotype classification via quadratic discriminant analysis (QDA). We herein propose a method for analyzing the exposure effects on the soft classification probabilities of the phenotypes via estimating equations. Under reasonable assumptions, the estimating equations are unbiased and lead to consistent estimators. The resulting estimator had good finite sample performances in simulation studies. As an illustrative example, we applied our proposed methods to assess the association between a dietary intake pattern, assessed as adherence scores for the dietary approaches to stop hypertension diet calculated using validated food-frequency questionnaires, and audiometric phenotypes (older-normal, metabolic, sensory, and metabolic plus sensory), determined based on data obtained in the Nurses' Health Study II Conservation of Hearing Study, the Audiology Assessment Arm. Our findings suggested that participants with a more healthful dietary pattern were less likely to develop the metabolic plus sensory phenotype of age-related hearing loss.

24-hour urine oxalate and risk of chronic kidney disease

BACKGROUND

To assess whether 24-hr urine oxalate (UOx) excretion is a risk factor for incident chronic kidney disease (CKD).

METHODS

This longitudinal observational US-based study included 426,896 individuals age ≥ 18 years with no CKD at baseline and with at least one UOx and at least 6 months of baseline and 6 months of follow-up data. Of these, 11,239 (2.6%) had an underlying malabsorptive condition. Incident CKD, defined by relevant ICD codes, was identified from a multi-source data cloud containing individual-level healthcare claims and electronic medical records data. The association between categories of UOx and incident CKD was modeled using logistic regression adjusting for age, sex, race, BMI, baseline urine calcium, urine citrate, urine volume, tobacco use, hypertension, diabetes, malabsorption, and cardiovascular disease.

RESULTS

Mean follow-up time was 38.9 months (SD 21.7). Compared with individuals with UOx <20 mg/24-hr, the odds of developing incident CKD increased for UOx 20-29 mg/24-hr (multivariate-adjusted (MV) OR: 1.14, 95% CI: 1.07, 1.21) through 80+ mg/24-hr (MVOR: 1.35 [1.21, 1.50] and was statistically significant for each UOx category. A similar pattern was seen in the subgroup with a malabsorptive condition though the magnitudes of association were larger, with the odds of developing incident CKD increased for UOx 20-29 mg/24-hr (MVOR: 1.50 [1.03, 2.20] through 80+ mg/24-hr (MVOR: 2.34 [1.50, 3.63] as compared with UOx <20 mg/24-hr.

CONCLUSIONS

The risk of incident CKD increases with increasing 24-hr urine oxalate excretion. Future studies should examine whether reducing urine oxalate diminishes the risk of developing CKD.

Analytical method for detecting outlier evaluators

BACKGROUND

Epidemiologic and medical studies often rely on evaluators to obtain measurements of exposures or outcomes for study participants, and valid estimates of associations depends on the quality of data. Even though statistical methods have been proposed to adjust for measurement errors, they often rely on unverifiable assumptions and could lead to biased estimates if those assumptions are violated. Therefore, methods for detecting potential 'outlier' evaluators are needed to improve data quality during data collection stage.

METHODS

In this paper, we propose a two-stage algorithm to detect 'outlier' evaluators whose evaluation results tend to be higher or lower than their counterparts. In the first stage, evaluators' effects are obtained by fitting a regression model. In the second stage, hypothesis tests are performed to detect 'outlier' evaluators, where we consider both the power of each hypothesis test and the false discovery rate (FDR) among all tests. We conduct an extensive simulation study to evaluate the proposed method, and illustrate the method by detecting potential 'outlier' audiologists in the data collection stage for the Audiology Assessment Arm of the Conservation of Hearing Study, an epidemiologic study for examining risk factors of hearing loss in the Nurses' Health Study II.

RESULTS

Our simulation study shows that our method not only can detect true 'outlier' evaluators, but also is less likely to falsely reject true 'normal' evaluators.

CONCLUSIONS

Our two-stage 'outlier' detection algorithm is a flexible approach that can effectively detect 'outlier' evaluators, and thus data quality can be improved during data collection stage.

Analytical methods for correlated data arising from multicenter hearing studies

In epidemiological hearing studies, estimating the association between exposures and hearing loss using audiometrically-assessed hearing measurements is challenging due to the complex correlation structure in the clustered data, with clusters formed by the two ears of the same individual and the testing site and audiologist. We propose a linear mixed-effects model to take into account the multilevel correlation structures of the data. Both theoretically and in simulation studies, we compare single-ear linear regression models commonly used in published hearing loss studies with the proposed both-ears linear mixed models properly accounting for the multi-level correlations. Our findings include (1) when there are only participant-level covariates, the worse-ear linear regression models produce unbiased but typically less efficient estimators than the both-ear and average-ear approaches; (2) when there are ear-level confounders, the worse-ear method may lead to biased estimators and the average-ear method produces unbiased but typically less efficient estimators than the both-ear method; (3) the both-ear method may gain efficiency when additionally adjusting for testing sites and audiologists. As an illustrative example, we applied the single-ear and both-ear methods to assess aspirin-hearing association in the Nurses' Health Study II.

POS0280 EXCESS RISK OF ALL-CAUSE AND CARDIOVASCULAR MORTALITY IN FEMALES WITH GOUT – A PROSPECTIVE COHORT STUDY OF 105,502 WOMEN

Background

Despite the disproportionately worsening disease burden of female gout in recent years1 and its frequent associations with key cardiovascular risk factors (more often than male gout2,3), there remains a paucity of specific data about female gout, particularly about its impact on mortality and fatal coronary heart disease (CHD).

Objectives

To prospectively examine the relation of female gout and risk of all-cause and cardiovascular and coronary heart disease-specific deaths.

Methods

Using data from the Nurses’ Health Study (NHS), an ongoing prospective cohort study in which female nurses in the United States completed detailed mailed questionnaires regarding their medical history, lifestyle, and other risk factors at baseline and every two years thereafter, we prospectively analyzed the relation between gout status at baseline and during the follow-up period and the risk of all-cause and cardiovascular mortality using Cox proportional hazards regression to adjust for cardiovascular risk factors such as comorbidities, body mass index, postmenopausal status, medication use, and dietary factors.

Results

The analysis included 105,502 women without gout and 1602 women with gout. Women with gout at baseline in 1982 tended to be older (mean age 54 vs. 50 years), and more likely to report a history of hypertension (44% vs. 22%), hypercholesterolemia (17% vs. 8%), and diabetes (11% vs. 6%). During 24 years of follow-up, we documented 15,255 deaths from all causes, including 3,128 deaths from cardiovascular disease (CVD) and 1,405 deaths from coronary heart disease (CHD). Compared to women without history of gout or CHD at baseline, the multivariable relative risks (RRs) among women with history of gout at baseline were 1.33 (95% CI, 1.21 to 1.46) for total mortality, 1.40 (95% CI, 1.17 to 1.67) for CVD deaths, and 1.49 (95% CI, 1.17 to 1.91) for fatal CHD (Table 1). The corresponding RRs for gout at baseline and during the follow-up were 1.33 (95% CI, 1.23 to 1.44), 1.43 (95% CI, 1.24 to 1.66), and 1.34 (95% CI, 1.08 to 1.66), respectively.

Table 1.

Relative Risks of Death from All-Causes, Cardiovascular Disease, and Coronary Heart Disease According to Gout Status at Baseline in 1982 in the Nurses’ Health Study

No CHDNo GoutGoutDeaths from all causesCases, n14,810445Age-adjusted RR (95% CI)1.01.58 (1.43, 1.73)Multivariable-adjusted* RR (95% CI)1.01.33 (1.21, 1.46)All cardiovascular deathsCases, n3,001127Age-adjusted RR (95% CI)1.02.06 (1.72, 2.46)Multivariable-adjusted* RR (95% CI)1.01.40 (1.17, 1.67)Fatal CHDCases, n1,33570Age-adjusted RR (95% CI)1.02.53 (1.99, 3.22)Multivariable-adjusted* RR (95% CI)1.01.49 (1.17, 1.91)

*Adjusted for age (continuous), history of hypertension, history of hypercholesterolemia, history of diabetes, aspirin use (yes, no), diuretic use (yes, no), smoking (never, past, current <15, current ≥15 cigarettes/day), body mass index (<23, 23-24.9, 25-29.9, 30-34.9, ≥35), physical activity (quintile), alcohol intake (nondrinker, <5, 5-9, 10-29, ≥30g/day), family history of MI (yes, no), menopausal status (premenopause, post menopause), hormone replacement therapy use (premenopause, never user, current user, past user). total energy intake (quintile), trans fat (quintile), dietary cholesterol (quintile), protein (quintile), linoleic fatty acid (quintile), and ratio of polyunsaturated fat/saturated fat.

CHD = coronary heart disease; CI = confidence interval; RR = relative risk.

Conclusion

These prospective data indicate that women with gout have a higher risk of all-cause mortality, which is primarily driven by higher risk of CVD deaths. These findings closely agree with the UK general population data of both sexes that showed unclosing mortality gap over the past two decades.4 Together, these findings provide support for rigorous cardiovascular risk factor modification specifically in female gout to help curtail the rising disease burden of gout worldwide.1

References

[1]Xia et al., PMID 31624843

[2]Puig et al., PMID 2012455

[3]Harrold et al., PMID 16644784

[4]Fisher et al., PMID 28122760

Disclosure of Interests

Chio Yokose: None declared, Natalie McCormick: None declared, Na Lu: None declared, Amit Joshi: None declared, Gary Curhan Consultant of: AstraZeneca, Allena Pharmaceuticals, Shire/Takeda, Dicerna, and Orfan, Grant/research support from: Decibel Therapeutics, Employee of: Chief Medical Officer at OM1, Inc., Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, and Vaxart, Grant/research support from: Ironwood and Horizon

Validation of a machine learning approach to estimate expanded disability status scale scores for multiple sclerosis

Background

Disability assessment using the Expanded Disability Status Scale (EDSS) is important to inform treatment decisions and monitor the progression of multiple sclerosis. Yet, EDSS scores are documented infrequently in electronic medical records.

Objective

To validate a machine learning model to estimate EDSS scores for multiple sclerosis patients using clinical notes from neurologists.

Methods

A machine learning model was developed to estimate EDSS scores on specific encounter dates using clinical notes from neurologist visits. The OM1 MS Registry data were used to create a training cohort of 2632 encounters and a separate validation cohort of 857 encounters, all with clinician-recorded EDSS scores. Model performance was assessed using the area under the receiver-operating-characteristic curve (AUC), positive predictive value (PPV), and negative predictive value (NPV), calculated using a binarized version of the outcome. The Spearman R and Pearson R values were calculated. The model was then applied to encounters without clinician-recorded EDSS scores in the MS Registry.

Results

The model had a PPV of 0.85, NPV of 0.85, and AUC of 0.91. The model had a Spearman R value of 0.75 and Pearson R value of 0.74 when evaluating performance using the continuous estimated EDSS and clinician-recorded EDSS scores. Application of the model to eligible encounters resulted in the generation of eEDSS scores for an additional 190,282 encounters from 13,249 patients.

Conclusion

EDSS scores can be estimated with very good performance using a machine learning model applied to clinical notes, thus increasing the utility of real-world data sources for research purposes.

Adherence to 2020 to 2025 Dietary Guidelines for Americans and the Risk of New-Onset Female Gout

IMPORTANCE

Female-specific gout data are scarce despite perceived differences from males in its risk factors and disproportionate worsening in disease and comorbidity burden globally. The 2020 to 2025 Dietary Guidelines for Americans recommend multiple healthy eating patterns for prevention of cardiovascular-metabolic outcomes, which may also be relevant to the prevention of female gout.

OBJECTIVE

To examine the associations of dietary scores for the latest guideline-based healthy eating patterns with risk of incident female gout.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study included 80 039 US women in the Nurses' Health Study followed up through questionnaires every 2 years starting from 1984. Participants had no history of gout at baseline, and the study used questionnaire responses through 2018. Statistical analyses were performed over September 2020 to August 2021.

EXPOSURES

Four healthy eating patterns: Dietary Approaches to Stop Hypertension (DASH), Alternate Mediterranean Diet Score, Alternative Healthy Eating Index (AHEI), and Prudent, plus Western (unhealthy) for comparison, with scores derived from validated food frequency questionnaires.

MAIN OUTCOMES AND MEASURES

Incident, physician-diagnosed female-specific gout.

RESULTS

During 34 years of follow-up, we documented 3890 cases of incident female gout. Compared with the least-adherent quintile, women most adherent to healthy diets had significantly lower risk of incident gout, with multivariable-adjusted hazard ratios (HRs) 0.68 (95% CI, 0.61-0.76) (DASH), 0.88 (95% CI, 0.80-0.98) (Mediterranean), 0.79 (95% CI, 0.71-0.89) (AHEI), and 0.75 (95% CI, 0.73-0.90) (Prudent); all P for trend ≤.009. Conversely, women with highest-quintile Western diet score had 49% higher risk of gout (HR, 1.49; 95% CI, 1.33-1.68], P <.001). When combined, the most DASH-diet adherent women with normal body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) had a 68% lower risk of gout compared with the least adherent women with overweight or obese BMI; the corresponding risk reduction was 65% combining high DASH diet adherence with no diuretic use.

CONCLUSIONS AND RELEVANCE

These large-scale, long-term prospective cohort findings extend the pleotropic benefits of the 2020 to 2025 Dietary Guidelines for Americans to female gout prevention, with multiple healthy diets that can be adapted to individual food traditions, preferences, and comorbidities.

Validation of a machine learning approach to estimate Clinical Disease Activity Index Scores for rheumatoid arthritis

OBJECTIVE

Disease activity measures, such as the Clinical Disease Activity Index (CDAI), are important tools for informing treatment decisions and monitoring patient outcomes in rheumatoid arthritis (RA). Yet, documentation of CDAI scores in electronic medical records and other real-world data sources is inconsistent, making it challenging to use these data for research. The purpose of this study was to validate a machine learning model to estimate CDAI scores for patients with RA using clinical notes.

METHODS

A machine learning model was developed to estimate CDAI score values using clinical notes from a specific rheumatology visit. Data from the OM1 RA Registry were used to create a training cohort of 56 177 encounters and a separate validation cohort of 18 726 encounters, 11 985 of which passed a model-derived confidence filter; all included encounters had both a clinician-recorded CDAI score and a clinical note. Model performance was assessed using the area under the receiver operating characteristic curve (AUC), positive predictive value (PPV) and negative predictive value (NPV), calculated using a binarised version of the outcome. The Spearman's R and Pearson's R values were also calculated.

RESULTS

The model had a PPV of 0.80, NPV of 0.84 and AUC of 0.88 when evaluating performance using the binarised version of the outcome. The model had a Spearman's R value of 0.72 and a Pearson's R value of 0.69 when evaluating performance using the continuous CDAI numeric scores.

CONCLUSION

A machine learning model estimates CDAI scores from clinical notes with good performance. Application of the model to real-world data sets may allow estimated CDAI scores to be used for research purposes.

Validation of a machine learning approach to estimate Systemic Lupus Erythematosus Disease Activity Index score categories and application in a real-world dataset

Objective

Use of the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) in routine clinical practice is inconsistent, and availability of clinician-recorded SLEDAI scores in real-world datasets is limited. This study aimed to validate a machine learning model to estimate SLEDAI score categories using clinical notes and to apply the model to a large, real-world dataset to generate estimated score categories for use in future research studies.

Methods

A machine learning model was developed to estimate an individual patient’s SLEDAI score category (no activity, mild activity, moderate activity or high/very high activity) for a specific encounter date using clinical notes. A training cohort of 3504 encounters and a separate validation cohort of 1576 encounters were created from the OM1 SLE Registry. Model performance was assessed using the area under the receiver operating characteristic curve (AUC), calculated using a binarised version of the outcome that sets the positive class to be those records with clinician-recorded SLEDAI scores >5 and the negative class to be records with scores ≤5. Model performance was evaluated by categorising the scores into the four disease activity categories and by calculating the Spearman’s R value and Pearson’s R value.

Results

The AUC for the two categories was 0.93 for the development cohort and 0.91 for the validation cohort. The model had a Spearman’s R value of 0.7 and a Pearson’s R value of 0.7 when calculated using the four disease activity categories.

Conclusion

The model performs well when estimating SLEDAI score categories using unstructured clinical notes.

Trends in the prevalence of kidney stones in the United States from 2007 to 2016

The overall prevalence of kidney stones (KS) in the US rose from 3.2% in 1980 to 10.1% in 2016, but the trends in important subgroups have not been reported. We examined the prevalence trends of KS in subgroups of age, sex and race in the US and identified relevant laboratory factors associated with a history of KS using National Health and Nutrition Examination Survey (NHANES) data. We conducted a cross-sectional study among 28,209 US adults aged ≥ 20 years old in the NHANES from 2007 to 2016. We calculated the prevalence of a self-reported history of KS by using weights and standardized to the 2010 US Census population. We also compared relevant laboratory values according to the history of KS. The prevalence of KS decreased from 8.7% in 2007-2008 to 7.2% in 2011-2012 but then increased to 9.0% in 2013-2014 and 10.1% in 2015-2016. However, the overall prevalence of KS increased over 2007-2016 (p-trend = 0.02). Prevalence of KS among men was higher than women. Among men aged 20-79, there were significant quadratic trends in the prevalence of KS. Whereas, the prevalence of KS increased as a linear trend among women aged 20-59 years over 2007-2016. There were no consistent trends in the prevalence of KS by race. The prevalence trend of KS among non-Hispanic whites was 9.8% from 2007 to 2010 then dropped to 7.9% in 2011-2012 and increased to 10.6% in 2013-2014 and 12.1% in 2015-2016. A similar trend was also observed among non-Hispanic blacks. Among Hispanic, the prevalence of KS was 7.6% in 2007-2008 and 7.4% in 2009-2010 and then fluctuated over the next several time periods. For non-Hispanic Asians, the range was 4.4-4.6%. Regarding relevant laboratory factors, after adjusting for sex, race, age, BMI, smoking status, alcohol drinking, history of diabetes and gout, urine albumin-creatinine ratio and serum osmolality were independently associated with the history of KS in women and men. In conclusion, there was substantial variability in KS prevalence across individual 2-year time periods. This variation of period-specific prevalence values emphasizes the importance of looking at long-term trends and using more than a single 2-year cycle in analyses to increase the precision of the estimate. However, there was an overall increase in the prevalence of KS over 2007-2016.

Effects of Low-Fat, Mediterranean, or Low-Carbohydrate Weight Loss Diets on Serum Urate and Cardiometabolic Risk Factors: A Secondary Analysis of the Dietary Intervention Randomized Controlled Trial (DIRECT)

OBJECTIVE

Weight loss diets may reduce serum urate (SU) by lowering insulin resistance while providing cardiometabolic benefits, something urate-lowering drugs have not shown in trials. We aimed to examine the effects of weight loss diets on SU and cardiometabolic risk factors.

RESEARCH DESIGN AND METHODS

This secondary study of the Dietary Intervention Randomized Controlled Trial (DIRECT) used stored samples from 235 participants with moderate obesity randomly assigned to low-fat, restricted-calorie (n = 85); Mediterranean, restricted-calorie (n = 76); or low-carbohydrate, non-restricted-calorie (n = 74) diets. We examined SU changes at 6 and 24 months overall and among those with hyperuricemia (SU ≥416 μmol/L), a relevant subgroup at risk for gout.

RESULTS

Among all participants, average SU decreases were 48 μmol/L at 6 months and 18 μmol/L at 24 months, with no differences between diets (P > 0.05). Body weight, HDL cholesterol (HDL-C), total cholesterol:HDL-C ratio, triglycerides, and insulin concentrations also improved in all three groups (P < 0.05 at 6 months). Adjusting for covariates, changes in weight and fasting plasma insulin concentrations remained associated with SU changes (P < 0.05). SU reductions among those with hyperuricemia were 113, 119, and 143 μmol/L at 6 months for low-fat, Mediterranean, and low-carbohydrate diets (all P for within-group comparison < 0.001; P > 0.05 for between-group comparisons) and 65, 77, and 83 μmol/L, respectively, at 24 months (all P for within-group comparison < 0.01; P > 0.05 for between-group comparisons).

CONCLUSIONS

Nonpurine-focused weight loss diets may simultaneously improve SU and cardiovascular risk factors likely mediated by reducing adiposity and insulin resistance. These dietary options could provide personalized pathways to suit patient comorbidity and preferences for adherence.

Disentangling the Relationships Between the Renin-Angiotensin-Aldosterone System, Calcium Physiology, and Risk for Kidney Stones

CONTEXT

Complex relationships between aldosterone and calcium homeostasis have been proposed.

OBJECTIVE

To disentangle the influence of aldosterone and intravascular volume on calcium physiology.

DESIGN

Patient-oriented and epidemiology studies.

SETTING

Clinical research center and nationwide cohorts.

PARTICIPANTS/INTERVENTIONS

Patient-oriented study (n = 18): Participants were evaluated after completing a sodium-restricted (RES) diet to contract intravascular volume and after a liberalized-sodium (LIB) diet to expand intravascular volume. Cross-sectional studies (n = 3755): the association between 24h urinary sodium and calcium excretion and risk for kidney stones was assessed.

RESULTS

Patient-oriented study: compared to a RES-diet, a LIB-diet suppressed renin activity (LIB: 0.3 [0.1, 0.4] vs. RES: 3.1 [1.7, 5.3] ng/mL/h; P < 0.001) and plasma aldosterone (LIB: 2.0 [2.0, 2.7] vs. RES: 20.0 [16.1, 31.0] vs. ng/dL; P < 0.001), but increased calciuria (LIB: 238.4 ± 112.3 vs. RES: 112.9 ± 60.8 mg/24hr; P < 0.0001) and decreased serum calcium (LIB: 8.9 ± 0.3 vs. RES: 9.8 ± 0.4 mg/dL; P < 0.0001). Epidemiology study: mean urinary calcium excretion was higher with greater urinary sodium excretion. Compared to a urinary sodium excretion of < 120 mEq/day, a urinary sodium excretion of ≥220 mEq/day was associated with a higher risk for having kidney stones in women (risk ratio = 1.79 [95% confidence interval 1.05, 3.04]) and men (risk ratio = 2.06 [95% confidence interval 1.27, 3.32]).

CONCLUSIONS

High dietary sodium intake suppresses aldosterone, decreases serum calcium, and increases calciuria and the risk for developing kidney stones. Our findings help disentangle the influences of volume from aldosterone on calcium homeostasis and provide support for the recommendation to restrict dietary sodium for kidney stone prevention.

FRI0186 JOINT INVOLVEMENT AND DISEASE ACTIVITY IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS: CALCULATION OF SWOLLEN TO TENDER JOINT COUNT RATIO IN A REAL WORLD COHORT IN THE US

Background:

Joint swelling and tenderness are common in patients with systemic lupus erythematosus (SLE). Swollen to tender joint count ratio (STR) is an index originally used in rheumatoid arthritis (RA) which assesses severity of disease activity based on 28 joint counts [1]. In RA, STR is a predictor of treatment response with a higher score indicating greater likelihood of responding.

Objectives:

To characterize SLE patients in a real-world cohort based on disease activity as defined by STR.

Methods:

The OM1 SLE Registry (OM1, Boston, MA) follows more than 37,000 SLE patients longitudinally with deep clinical data, including laboratory, patient-reported and disease activity information, and linked administrative claims, starting from 2013. Patients ≥16 years of age with swollen and tender joint counts based on 28 joints on the same encounter were included. STRs were calculated by inserting 1 if the denominator was 0 [2]. Patients were categorized by first available STR as having low (STR <0.5), moderate (0.5 ≤ STR ≤ 1.0), and high (STR >1.0) disease activity. Clinical characteristics were summarized by disease activity group. Definitions of SLE treatments were based on 2019 EULAR recommendations [3].

Results:

As of December 2019, there were 9,919 patients with at least one STR available in the OM1 SLE Registry. STR was low in 80.4%, moderate in 12.2%, and high in 7.4% of patients. Mean age overall was 52.1 years (standard deviation: 14.8), 92.1% were female, and 71.8% of 7,730 patients with known race were white. Clinical characteristics by STR group are described in Table 1. Antimalarial use decreased and immunosuppressant use increased with increasing STR. Use of select disease-modifying antirheumatic drugs (DMARDs) was higher among patients with moderate or high STR. Lupus nephritis was more common in patients with low STR. A higher proportion of patients with moderate STR had osteoarthritis. The proportion of patients with anxiety and depression decreased with increasing STR. On average, patient and physician global assessments from MDHAQ were higher for patients with moderate STR.

Table 1.

Clinical characteristics of patients with SLE by swollen:tender joint count ratio group

LowSTR <0.5(N=7,970)Moderate0.5 ≤ STR ≤ 1.0(N=1,211)HighSTR >1.0(N=738)Treatment prior to STR, n (%) Antimalarial5,106 (64.1%)702 (58.0%)427 (57.9%) Biologics (belimumab or rituximab)662 (8.3%)113 (9.3%)70 (9.5%) Immunosuppressants2,310 (29.0%)398 (32.9%)252 (34.1%) Select DMARDs635 (8.0%)165 (13.6%)94 (12.7%) Steroids4,437 (55.7%)785 (64.8%)434 (58.8%)Disease conditions prior to STR, n (%) Anxiety266 (3.3%)25 (2.1%)12 (1.6%) Depression1,127 (14.1%)149 (12.3%)80 (10.8%) Lupus nephritis984 (12.3%)117 (9.7%)72 (9.8%) Osteoarthritis2,336 (29.3%)393 (32.5%)193 (26.2%) Osteoporosis631 (7.9%)95 (7.8%)47 (6.4%)MDHAQ, N1,991388230MDHAQ, mean (SD) Patient global assessment (0-10)4.5 (2.9)5.3 (2.7)4.4 (2.8) Physician global assessment (0-10)2.8 (2.7)3.8 (2.6)2.8 (2.3)

Conclusion:

Differences in treatments received were apparent between patients of varying disease activity groups with trends towards increased use among patients with higher disease activity. Additional research is needed to determine the utility of this measure for assessing SLE-related outcomes.

References:

[1]Cipriano et al., Reumatismo 2015 Sept 16;67(2):62-7

[2]Hammer HB et al., Arthritis Rheumatol 2016; 68 (suppl 10)

[3]Fanouriakis et al., Ann Rheum Dis. 2019;78:736-745

Disclosure of Interests:

None declared

Fish and marine fatty acids intakes, the FADS genotypes and long-term weight gain: a prospective cohort study

OBJECTIVE

We tested whether genetic variants near fatty acid desaturases gene (FADS) cluster, which were recently identified to be signatures of adaptation to fish-rich and n-3 polyunsaturated fatty acids (PUFAs)-rich diet, interacted with these dietary factors on change in body mass index (BMI).

DESIGN

Three FADS variants were examined for gene-diet interactions on long-term (~10 years) changes in BMI and body weight in four prospective cohort studies.

SETTING

Population based study.

PARTICIPANTS

11 323 women from the Nurses' Health Study (NHS), 6833 men from the Health Professionals Follow-up Study (HPFS) and replicated in 6254 women from the Women's Health Initiative (WHI) and 5 264 Chinese from the Singapore Chinese Health Study (SCHS).

MAIN OUTCOMES

Long-term (~10 years) changes in BMI and body weight.

RESULTS

In the NHS and HPFS cohorts, food-sourced n-3 PUFAs intake showed interactions with the FADS rs174570 on changes of BMI (P for interaction=0.02 in NHS, 0.05 in HPFS and 0.007 in combined). Such interactions were replicated in two independent cohorts WHI and SCHS (P for interaction=0.04 in WHI, 0.02 in SCHS and 0.001 in combined). The genetic associations of the FADS rs174570 with changes in BMI increased across the tertiles of n-3 PUFAs in all the cohorts. Fish intake also accentuated the genetic associations of the FADS rs174570 with long-term changes in BMI (pooled P for interaction=0.006). Viewed differently, long chain n-3 PUFAs intake showed stronger association with long-term changes in BMI among the rs174570 T carriers (beta=0.79 kg/m² per g, p=3×10^-5) than the rs174570 non-T carriers (beta=0.16 kg/m² per g, p=0.08). Similar results were observed for fish intake.

CONCLUSIONS

Our hypothesis-driven analyses provide replicable evidence that long chain n-3 PUFAs and fish intakes may interact with the FADS variant on long-term weight gain. Further investigation is needed to confirm our findings in other cohorts.

MON-522 Risk of Chronic Kidney Disease (CKD) and Its Progression in Patients with Chronic Hypoparathyroidism (HypoPT)

Background: Chronic hypoparathyroidism (HypoPT) managed with conventional therapy (i.e., oral calcium and active vitamin D) may potentially increase the risk of chronic kidney disease (CKD) stage ≥ 3 and accelerate CKD stage progression, including progression to end stage kidney disease (ESKD) (i.e., CKD stage 5 or dialysis). Methods: A retrospective cohort study was conducted to compare the risk of CKD between chronic HypoPT patients (excluding those receiving parathyroid hormone) and randomly selected non-HypoPT patients over 5 years of follow-up using a large US commercial claims database (Q1 2007 - Q2 2017). The first date of follow-up (i.e., index date) for HypoPT patients was the earliest HypoPT diagnosis date at least 6 months after the initial HypoPT diagnosis and for non-HypoPT patients was the date of a randomly selected medical claim. Patient characteristics at baseline (the 6 months prior to index date) were compared between cohorts. CKD stages were identified by diagnosis codes, estimated glomerular filtration rate (eGFR) lab values (calculated using the CKD-EPI formula), and dialysis procedure codes. Among those free of CKD at baseline, the risk of incident CKD stage ≥ 3 was compared between cohorts using Kaplan-Meier analysis and adjusted Cox proportional hazards models. Adjusting parameters included demographic (age, sex, race, region, and index year) and clinical (heart failure, hypertension, diabetes, and medication use) characteristics at baseline. Similar analyses were conducted for CKD progression to a higher CKD stage and to ESKD, among patients with baseline CKD stages 3 or 4. Results: A total of 8,097 chronic HypoPT and 40,485 non-HypoPT patients were included. Compared to non-HypoPT patients, HypoPT patients were older (58.6 vs. 47.3 years), a higher proportion were female (76.2 vs. 54.4%), and a higher proportion had CKD stages 3-5 (16.4 vs. 3.0%) and stages 3-4 (13.6 vs. 2.6%) at baseline. Among those with baseline CKD stages 3-4, HypoPT patients were younger (70.6 vs. 72.1 years) and a higher proportion were female (67.1 vs. 54.8%) compared to non-HypoPT patients. Kaplan-Meier analyses showed that HypoPT patients had significant increased risk of CKD stage 3 and higher, CKD progression, and progression to ESKD compared to non-HypoPT patients (all p<0.001). The adjusted hazard ratios (HRs) associated with HypoPT vs. non-HypoPT were 2.57 (95% confidence interval [CI]: 2.35, 2.82) for CKD stage ≥ 3, 1.62 (1.29, 2.03) for CKD progression, and 1.95 (1.41, 2.70) for progression to ESKD (all p<0.001). Conclusions: Chronic HypoPT was associated with significant increased risk of CKD stage ≥ 3 and CKD stage progression, including progression to ESKD. Further research is warranted to understand the potential mechanisms for the relationship of chronic HypoPT and its management with these observed risks. Funding: Shire

MON-524 Risk of Decline in Estimated Glomerular Filtration Rate (eGFR) in Patients with Chronic Hypoparathyroidism (HypoPT)

Background: Chronic hypoparathyroidism (HypoPT) managed with conventional therapy (i.e., oral calcium and active vitamin D) may potentially impact renal function. This study evaluated whether chronic HypoPT is associated with increased rate of estimated glomerular filtration rate (eGFR) decline. Methods: A retrospective cohort study was conducted to compare eGFR decline between chronic HypoPT patients (excluding those receiving parathyroid hormone) and randomly selected non-HypoPT patients over 5 years of follow-up using a large commercial claims database (Q1 2007 - Q2 2017). The first date of follow-up (i.e., index date) for HypoPT patients was the earliest HypoPT diagnosis date at least 6 months after the initial HypoPT diagnosis and for non-HypoPT patients was the date of a randomly selected medical claim. All patients were required to have eGFR values (calculated using the CKD-EPI formula) recorded during baseline (the six months prior to index date). The risk of eGFR decline ≥ 10 mL/min/1.73 m² was compared between cohorts using Kaplan-Meier analysis and adjusted Cox proportional hazards models. Adjusting parameters included demographic (age, sex, race, region, and index year) and clinical (eGFR, heart failure, hypertension, diabetes, and medication use) characteristics at baseline. Subgroup analyses were performed among patients with baseline eGFR ≥ 60 and < 60 mL/min/1.73 m². A sensitivity analysis was conducted among the subset of patients with ≥ 1 study period eGFR value in addition to baseline eGFR. Results: A total of 1,880 chronic HypoPT and 4,414 non-HypoPT patients met the study criteria. Compared to non-HypoPT patients, HypoPT patients were older (59.7 vs. 54.0 years) and a higher proportion were female (75.1 vs. 56.2%). At baseline, HypoPT patients had lower median eGFR (75.2 vs. 87.9 mL/min/1.73 m²) and a higher proportion had history of heart failure, hypertension, and type 2 diabetes compared to non-HypoPT patients. Kaplan-Meier analyses showed that, compared to non-HypoPT patients, HypoPT patients had an increased rate of eGFR decline among all patients, in the subgroups with baseline eGFR ≥ and < 60mL/min/1.73m², and among the sensitivity cohort with baseline and study period eGFR (all p<0.001). The adjusted hazard ratios (HRs) of eGFR decline ≥ 10mL/min/1.73 m² for HypoPT vs. non-HypoPT were 1.97 (95% confidence interval [CI]: 1.75, 2.21) among all patients, 2.10 (1.84, 2.38) among those with baseline eGFR ≥ 60, 1.74 (1.29, 2.34) among those with baseline eGFR < 60, and 1.51 (1.35, 1.70) among the sensitivity cohort (all p<0.001). Conclusions: Chronic HypoPT was associated with an increased rate of eGFR decline. Further research is warranted to understand the potential mechanisms for the relationship of chronic HypoPT and its management with the observed decline in eGFR. Funding: Shire

MON-526 Risk of Cardiovascular (CV) Conditions in Patients with Chronic Hypoparathyroidism (HypoPT)

Background: Chronic hypoparathyroidism (HypoPT) managed with conventional therapy (i.e., oral calcium and active vitamin D) may potentially increase the risk of cardiovascular (CV) conditions. This study evaluated whether chronic HypoPT is associated with increased risk of various CV conditions. Methods: A retrospective cohort study was conducted to compare the risk of CV conditions between chronic HypoPT patients (excluding those receiving parathyroid hormone) and randomly selected non-HypoPT patients over 5 years of follow-up using a large US commercial claims database (Q1 2007 - Q2 2017). CV conditions in this analysis included atrial fibrillation (AF), cerebrovascular disease, coronary artery disease (CAD), heart failure (HF), peripheral vascular disease (PVD), tachyarrhythmia, and a composite endpoint of related pathophysiology (i.e., cerebrovascular disease, CAD, HF, and PVD). The first date of follow-up (i.e., index date) for HypoPT patients was the earliest HypoPT diagnosis date at least 6 months after the initial HypoPT diagnosis and for non-HypoPT patients was the date of a randomly selected medical claim. Patient characteristics at baseline (the 6 months prior to index date) were compared between cohorts. Among those free of each CV condition at baseline, the risks of first occurrence of each condition during the study period were compared using Kaplan-Meier analysis and adjusted Cox proportional hazards models. Adjusting parameters included demographic (age, sex, race, region, and index year) and clinical (other comorbid CV conditions, chronic kidney disease, hypertension, and diabetes) characteristics at baseline. Results: A total of 8,097 HypoPT and 40,485 non-HypoPT patients were included. Overall, HypoPT patients were older (58.6 vs. 47.3 years), a higher proportion were female (76.2 vs. 54.4%), and a higher proportion had AF (6.0 vs. 2.7%), cerebrovascular disease (6.0 vs. 3.0%), CAD (9.6 vs. 5.3%), HF (5.9 vs. 2.4%), PVD (7.4 vs. 2.8%), and tachyarrhythmia (0.7 vs. 0.4%) at baseline. Kaplan-Meier analyses showed that HypoPT patients had increased risk of new occurrence of each CV condition and the composite CV endpoint compared to non-HypoPT patients (all p<0.001). The adjusted hazard ratios (HRs) associated with HypoPT vs. non-HypoPT were 1.70 (95% confidence interval [CI]: 1.48, 1.94) for AF, 1.47 (1.34, 1.61) for cerebrovascular disease, 1.42 (1.29, 1.57) for CAD, 1.63 (1.46, 1.83) for HF, 1.66 (1.51, 1.82) for PVD, 1.68 (1.32, 2.14) for tachyarrhythmia, and 1.64 (1.53, 1.76) for the composite CV endpoint. Conclusions: Chronic HypoPT was associated with significant increased risk of CV conditions. Further research is warranted to understand the potential mechanisms for the relationship of chronic HypoPT and its management with the observed risk. Funding: Shire

MON-523 Risk of Nephrolithiasis and Nephrocalcinosis in Patients with Chronic Hypoparathyroidism (HypoPT)

Background: Chronic hypoparathyroidism (HypoPT) managed with conventional therapy (i.e., oral calcium and active vitamin D) may increase the risk of nephrolithiasis and nephrocalcinosis. This study evaluated whether HypoPT is associated with increased risk of these conditions. Methods: A retrospective cohort study was conducted to compare the risk of nephrolithiasis and nephrocalcinosis between chronic HypoPT patients (excluding those receiving parathyroid hormone) and randomly selected non-HypoPT patients over 5 years of follow-up using a large US commercial claims database (Q1 2007 - Q2 2017). The first date of follow up (i.e., index date) for HypoPT patients was the earliest HypoPT diagnosis date at least 6 months after the initial HypoPT diagnosis and for non-HypoPT patients was the date of a randomly selected medical claim. Patient characteristics at baseline (the 6 months prior to index date) were compared between cohorts. The risk of nephrolithiasis (identified by diagnosis and procedure codes) was compared between cohorts using Kaplan-Meier analysis and adjusted Cox proportional hazards models. Adjusting parameters included demographic (age, sex, race, region, and index year) and clinical (nephrolithiasis, gout, hypercalciuria, hypertension, diabetes, and thiazide diuretic use) characteristics at baseline. Similar analyses were conducted for nephrocalcinosis, among those without the condition at baseline. Adjusting parameters included demographic information and hypercalciuria. A sensitivity analysis for nephrocalcinosis was conducted among those with study period kidney imaging. Results: A total of 8,097 chronic HypoPT patients and 40,485 non-HypoPT patients were included. Compared to non-HypoPT patients, HypoPT patients were older (58.6 vs. 47.3 years), a higher proportion were female (76.2 vs. 54.4%), and higher proportions had nephrolithiasis (3.3 vs. 1.3%), nephrocalcinosis (0.6 vs. <0.1%), gout (3.0 vs. 1.2%), hypercalciuria (23.8 vs. 0.5%), type 2 diabetes (20.6 vs. 10.8%), and hypertension (43.7 vs. 25.2%) at baseline (all p <0.001). Kaplan-Meier analyses showed that HypoPT patients had increased risk of nephrolithiasis and nephrocalcinosis vs. non-HypoPT patients (p<0.001). The adjusted hazard ratios (HRs) associated with HypoPT vs. non-HypoPT were 1.81 (95% confidence interval [CI]: 1.60, 2.04) for nephrolithiasis and 6.94 (4.41, 10.92) for nephrocalcinosis (both p<0.001). In the sensitivity analysis, 2.6% of HypoPT and 0.5% of non-HypoPT patients (p<0.001) had nephrocalcinosis during the study. Conclusions: Chronic HypoPT was associated with increased risks of nephrolithiasis and nephrocalcinosis. Further research is warranted to understand the potential mechanisms for the relationship of chronic HypoPT and its management with the observed risk of these conditions. Funding: Shire

OR04-1 Dietary Sodium Intake, the Renin-Angiotensin-Aldosterone System, and the Risk for Incident Kidney Stones

Context: We previously reported that acute changes in dietary sodium intake and renin-angiotensin-aldosterone system (RAAS) activity could substantially modulate calcium homeostasis. We demonstrated that humans consuming a high sodium diet for one week, compared with a restricted sodium diet for one week, had suppression of the RAAS, a ~100% increase in calciuria (P<0.0001), and a ~10% decrease in serum calcium (P<0.0001). Whether these marked and acute changes induced by high dietary sodium intake are sustained chronically is not known. We hypothesized that a high dietary sodium intake over many years could increase calciuria and the risk for incident kidney stones. Methods: We studied 2496 participants from the Health Professionals Follow-up Study (HPFS) (all men) and the Nurses’ Health Study I (NHSI) (all women). 24-hour urine samples, collected from participants confirmed to have kidney stones and appropriate controls, were assessed for calcium, sodium, creatinine, as well as other factors. Participants were categorized by 24-hour urinary sodium excretion (<120, 120-139, 140-159, 160-179, 180-199, 200-219, >/=220 mEq/day) and the relative risk for developing kidney stones was assessed for each category of sodium excretion via adjusted logistic regression models. Models were adjusted for age, history of hypertension, and numerous urinary parameters (volume, creatinine, oxalate, uric acid, citrate, magnesium, potassium, phosphorus, and pH). Adjustment for urinary calcium was performed to evaluate the role of calciuria in modifying the relation between urinary sodium excretion and kidney stones. Results: Mean adjusted urinary calcium levels for individuals with urinary sodium excretion of <120 mEq/day compared to >/=220 mEq/day were 178 (SD=73) vs. 228 (SD=91) mg/day in men and 161 (SD=60) vs. 208 (SD=80) mg/day in women. When compared with a urinary sodium excretion of <120 mEq/day (relative risk=1.00), having a urinary sodium excretion of >/=220 mEq/day was associated with a higher risk for incident kidney stones in men [RR=1.90 (95% CI 1.18, 3.05)] and women [RR=2.02 (95% CI 1.19, 3.43)]. These associations were attenuated and no longer statistically significant after adjusting for urinary calcium excretion, thereby suggesting that developing kidney stones was mediated, in part, through an increase in urinary calcium excretion when urinary sodium excretion was higher. Conclusion: The combination of our physiology and epidemiology studies suggest that higher dietary sodium intake, and concomitant suppression of the RAAS, result in increased calciuria and an approximately two-fold higher risk for developing kidney stones. Studies to evaluate dietary sodium restriction, and/or RAAS inhibition, as potential methods to decrease calciuria and kidney stones are warranted.

Relative Supersaturation of 24-Hour Urine and Likelihood of Kidney Stones

PURPOSE

The relative supersaturation of calcium oxalate, calcium phosphate and uric acid is used clinically in kidney stone prevention. The magnitude of the association between relative supersaturation and stone risk requires further quantification.

MATERIALS AND METHODS

We performed a cross-sectional study using 24-hour urine collections from the NHS (Nurses' Health Study) I and II, and HPFS (Health Professionals Follow-up Study) cohorts to quantify the association between the relative supersaturation of calcium oxalate, calcium phosphate and uric acid, and the likelihood of stone formation.

RESULTS

The OR of being a stone former was 5.85 (95% CI 3.40-10.04) in NHS I, 6.38 (95% CI 3.72-11.0) in NHS II and 6.95 (95% CI 3.56-13.6) in HPFS for the highest category of calcium oxalate relative supersaturation compared with less than 1.0. The OR of being a stone former was 1.86 (95% CI 0.94-3.71) in NHS I, 4.37 (95% CI 2.68-7.10) in NHS II and 3.59 (95% CI 2.04-6.31) in HPFS for the highest category of calcium phosphate relative supersaturation compared with less than 1.0. For uric acid relative supersaturation the OR of being a stone former was 4.30 (95% CI 2.34-7.90) in NHS I and 2.74 (95% CI 1.71-4.40) in NHS II for the highest relative supersaturation category compared with less than 1.0. In HPFS the uric acid relative supersaturation was not significantly associated with the likelihood of stone formation.

CONCLUSIONS

The likelihood of being a stone former increases with higher relative supersaturation of calcium oxalate and calcium phosphate in men and women, and with higher relative supersaturation of uric acid in women.

Low Bone Density and Bisphosphonate Use and the Risk of Kidney Stones

BACKGROUND AND OBJECTIVES

Previous studies have demonstrated lower bone density in patients with kidney stones, but no longitudinal studies have evaluated kidney stone risk in individuals with low bone density. Small studies with short follow-up reported reduced 24-hour urine calcium excretion with bisphosphonate use. We examined history of low bone density and bisphosphonate use and the risk of incident kidney stone as well as the association with 24-hour calcium excretion.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a prospective analysis of 96,092 women in the Nurses' Health Study II. We used Cox proportional hazards models to adjust for age, body mass index, thiazide use, fluid intake, supplemental calcium use, and dietary factors. We also conducted a cross-sectional analysis of 2294 participants using multivariable linear regression to compare 24-hour urinary calcium excretion between participants with and without a history of low bone density, and among 458 participants with low bone density, with and without bisphosphonate use.

RESULTS

We identified 2564 incident stones during 1,179,860 person-years of follow-up. The multivariable adjusted relative risk for an incident kidney stone for participants with history of low bone density compared with participants without was 1.39 (95% confidence interval [95% CI], 1.20 to 1.62). Among participants with low bone density, the multivariable adjusted relative risk for an incident kidney stone for bisphosphonate users was 0.68 (95% CI, 0.48 to 0.98). In the cross-sectional analysis of 24-hour urine calcium excretion, the multivariable adjusted mean difference in 24-hour calcium was 10 mg/d (95% CI, 1 to 19) higher for participants with history of low bone density. However, among participants with history of low bone density, there was no association between bisphosphonate use and 24-hour calcium with multivariable adjusted mean difference in 24-hour calcium of -2 mg/d (95% CI, -25 to 20).

CONCLUSIONS

Low bone density is an independent risk factor for incident kidney stone and is associated with higher 24-hour urine calcium excretion. Among participants with low bone density, bisphosphonate use was associated with lower risk of incident kidney stone but was not independently associated with 24-hour urine calcium excretion.

Sleep and CKD in Chinese Adults: A Cross-Sectional Study

BACKGROUND AND OBJECTIVES

To assess the association between self-reported sleep duration and quality and odds of having CKD in Chinese adults on the basis of a community study.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this cross-sectional study, we included 11,040 Chinese adults who participated in an ongoing prospective study, the Kailuan cohort. Survey questionnaire items addressed insomnia, daytime sleepiness, snoring, and sleep duration during their 2012 interview. Overall sleep quality was evaluated by summarizing these four sleep parameters. Fasting blood samples and single random midstream morning urine samples were collected in 2012 and analyzed for serum creatinine and proteinuria. CKD was defined by eGFR<60 ml/min per 1.73 m2 or proteinuria >300 mg/dl. We also examined those at high or very high risk of having CKD, on the basis of the Kidney Disease Improving Global Outcomes recommendations. The association between sleep quality and CKD was assessed using logistic regression model.

RESULTS

Worse overall sleep quality was associated with higher likelihood of being high or very high risk for CKD (multiadjusted odds ratio, 2.69; 95% confidence interval, 1.30 to 5.59 comparing two extreme categories; P trend <0.01), but not overall CKD (multiadjusted odds ratio, 1.58; 95% confidence interval, 0.89 to 2.80 comparing two extreme categories; P trend =0.46), after adjusting for potential confounders. Specifically, individuals with worse sleep quality were more likely to have proteinuria (multiadjusted odds ratio, 1.95; 95% confidence interval, 1.03 to 3.67 comparing two extreme categories; P trend =0.02), rather than lower eGFR level (multiadjusted mean eGFR levels were 96.4 and 93.6 ml/min per 1.73 m2 in the two extreme sleep categories, respectively; P trend =0.13). However, there was no statistically significant association between individual sleep parameters and CKD status.

CONCLUSIONS

Worse overall sleep quality was associated with higher odds of being high or very high risk for CKD and proteinuria in Chinese adults.

Renin Phenotypes Characterize Vascular Disease, Autonomous Aldosteronism, and Mineralocorticoid Receptor Activity

CONTEXT

Mild cases of autonomous aldosterone secretion may go unrecognized using current diagnostic criteria for primary aldosteronism (PA).

OBJECTIVE

To investigate whether the inability to stimulate renin serves as a biomarker for unrecognized autonomous aldosterone secretion and mineralocorticoid receptor (MR) activation.

PARTICIPANTS

Six hundred sixty-three normotensive and mildly hypertensive participants, who were confirmed to not have PA using current guideline criteria and were on no antihypertensive medications.

DESIGN

Participants had their maximally stimulated plasma renin activity (PRA) measured while standing upright after sodium restriction. Tertiles of maximally stimulated PRA were hypothesized to reflect the degree of MR activation: lowest PRA tertile = "Inappropriate/Excess MR Activity;" middle PRA tertile = "Intermediate MR Activity;"; and highest PRA tertile = "Physiologic MR Activity." All participants underwent detailed biochemical and vascular characterizations under conditions of liberalized sodium intake, and associations with stimulated PRA phenotypes were performed.

RESULTS

Participants with lower stimulated PRA had greater autonomous aldosterone secretion [higher aldosterone-to-renin ratio (P = 0.002), higher urine aldosterone excretion rate (P = 0.003), higher systolic blood pressure (P = 0.004), and lower renal plasma flow (P = 0.04)] and a nonsignificant trend toward lower serum potassium and higher urine potassium excretion, which became significant after stratification by hypertension status.

CONCLUSIONS

In participants without clinical PA, the inability to stimulate renin was associated with greater autonomous aldosterone secretion, impaired vascular function, and suggestive trends in potassium handling that indicate an extensive spectrum of unrecognized MR activation.

Effect of Uric Acid Lowering on Renin-Angiotensin-System Activation and Ambulatory BP: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Higher serum uric acid levels, even within the reference range, are strongly associated with increased activity of the renin-angiotensin system (RAS) and risk of incident hypertension. However, the effect of lowering serum uric acid on RAS activity in humans is unknown, although the data that lowering serum uric acid can reduce BP are conflicting.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a double-blind placebo-controlled trial conducted from 2011 to 2015, we randomly assigned 149 overweight or obese adults with serum uric acid ≥5.0 mg/dl to uric acid lowering with either probenecid or allopurinol, or to placebo. The primary endpoints were kidney-specific and systemic RAS activity. Secondary endpoints included mean 24-hour systolic BP, mean awake and asleep BP, and nocturnal dipping.

RESULTS

Allopurinol and probenecid markedly lowered serum uric acid after 4 and 8 weeks compared with placebo (mean serum uric acid in allopurinol, probenecid, and placebo at 8 weeks was 2.9, 3.5, and 5.6 mg/dl, respectively). The change in kidney-specific RAS activity, measured as change in the median (interquartile range) renal plasma flow response to captopril (in ml/min per 1.73 m2) from baseline to 8 weeks, was -4 (-25 to 32) in the probenecid group (P=0.83), -4 (-16 to 9) in the allopurinol group (P=0.32), and 1 (-21 to 17) in the placebo group (P=0.96), with no significant treatment effect (P=0.77). Similarly, plasma renin activity and plasma angiotensin II levels did not significantly change with treatment. The change in mean (±SD) 24-hour systolic BPs from baseline to 8 weeks was -1.6±10.1 with probenecid (P=0.43), -0.4±6.1 with allopurinol (P=0.76), and 0.5±6.0 with placebo (P=0.65); there was no significant treatment effect (P=0.58). Adverse events occurred in 9%, 12%, and 2% of those given probenecid, allopurinol, or placebo, respectively.

CONCLUSIONS

In contrast to animal experiments and observational studies, this randomized, placebo-controlled trial found that uric acid lowering had no effect on kidney-specific or systemic RAS activity after 8 weeks or on mean systolic BP. These data do not support the hypothesis that higher levels of uric acid are a reversible risk factor for increased BP.

A comprehensive survey of genetic variation in 20,691 subjects from four large cohorts

The Nurses' Health Study (NHS), Nurses' Health Study II (NHSII), Health Professionals Follow Up Study (HPFS) and the Physicians Health Study (PHS) have collected detailed longitudinal data on multiple exposures and traits for approximately 310,000 study participants over the last 35 years. Over 160,000 study participants across the cohorts have donated a DNA sample and to date, 20,691 subjects have been genotyped as part of genome-wide association studies (GWAS) of twelve primary outcomes. However, these studies utilized six different GWAS arrays making it difficult to conduct analyses of secondary phenotypes or share controls across studies. To allow for secondary analyses of these data, we have created three new datasets merged by platform family and performed imputation using a common reference panel, the 1,000 Genomes Phase I release. Here, we describe the methodology behind the data merging and imputation and present imputation quality statistics and association results from two GWAS of secondary phenotypes (body mass index (BMI) and venous thromboembolism (VTE)). We observed the strongest BMI association for the FTO SNP rs55872725 (β = 0.45, p = 3.48x10-22), and using a significance level of p = 0.05, we replicated 19 out of 32 known BMI SNPs. For VTE, we observed the strongest association for the rs2040445 SNP (OR = 2.17, 95% CI: 1.79-2.63, p = 2.70x10-15), located downstream of F5 and also observed significant associations for the known ABO and F11 regions. This pooled resource can be used to maximize power in GWAS of phenotypes collected across the cohorts and for studying gene-environment interactions as well as rare phenotypes and genotypes.

Four Susceptibility Loci for Gallstone Disease Identified in a Meta-analysis of Genome-Wide Association Studies

BACKGROUND & AIMS

A genome-wide association study (GWAS) of 280 cases identified the hepatic cholesterol transporter ABCG8 as a locus associated with risk for gallstone disease, but findings have not been reported from any other GWAS of this phenotype. We performed a large-scale, meta-analysis of GWASs of individuals of European ancestry with available prior genotype data, to identify additional genetic risk factors for gallstone disease.

METHODS

We obtained per-allele odds ratio (OR) and standard error estimates using age- and sex-adjusted logistic regression models within each of the 10 discovery studies (8720 cases and 55,152 controls). We performed an inverse variance weighted, fixed-effects meta-analysis of study-specific estimates to identify single-nucleotide polymorphisms that were associated independently with gallstone disease. Associations were replicated in 6489 cases and 62,797 controls.

RESULTS

We observed independent associations for 2 single-nucleotide polymorphisms at the ABCG8 locus: rs11887534 (OR, 1.69; 95% confidence interval [CI], 1.54-1.86; P = 2.44 × 10(-60)) and rs4245791 (OR, 1.27; P = 1.90 × 10(-34)). We also identified and/or replicated associations for rs9843304 in TM4SF4 (OR, 1.12; 95% CI, 1.08-1.16; P = 6.09 × 10(-11)), rs2547231 in SULT2A1 (encodes a sulfoconjugation enzyme that acts on hydroxysteroids and cholesterol-derived sterol bile acids) (OR, 1.17; 95% CI, 1.12-1.21; P = 2.24 × 10(-10)), rs1260326 in glucokinase regulatory protein (OR, 1.12; 95% CI, 1.07-1.17; P = 2.55 × 10(-10)), and rs6471717 near CYP7A1 (encodes an enzyme that catalyzes conversion of cholesterol to primary bile acids) (OR, 1.11; 95% CI, 1.08-1.15; P = 8.84 × 10(-9)). Among individuals of African American and Hispanic American ancestry, rs11887534 and rs4245791 were associated positively with gallstone disease risk, whereas the association for the rs1260326 variant was inverse.

CONCLUSIONS

In this large-scale GWAS of gallstone disease, we identified 4 loci in genes that have putative functions in cholesterol metabolism and transport, and sulfonylation of bile acids or hydroxysteroids.

Genome-wide association analysis identifies TXNRD2, ATXN2 and FOXC1 as susceptibility loci for primary open-angle glaucoma

Primary open angle glaucoma (POAG) is a leading cause of blindness world-wide. To identify new susceptibility loci, we meta-analyzed GWAS results from 8 independent studies from the United States (3,853 cases and 33,480 controls) and investigated the most significant SNPs in two Australian studies (1,252 cases and 2,592 controls), 3 European studies (875 cases and 4,107 controls) and a Singaporean Chinese study (1,037 cases and 2,543 controls). A meta-analysis of top SNPs identified three novel loci: rs35934224[T] within TXNRD2 (odds ratio (OR) = 0.78, P = 4.05×10⁻¹¹ encoding a mitochondrial protein required for redox homeostasis; rs7137828[T] within ATXN2 (OR = 1.17, P = 8.73×10⁻¹⁰), and rs2745572[A] upstream of FOXC1 (OR = 1.17, P = 1.76×10⁻¹⁰). Using RT-PCR and immunohistochemistry, we show TXNRD2 and ATXN2 expression in retinal ganglion cells and the optic nerve head. These results identify new pathways underlying POAG susceptibility and suggest novel targets for preventative therapies.

Genome-wide meta-analysis identifies six novel loci associated with habitual coffee consumption

Coffee, a major dietary source of caffeine, is among the most widely consumed beverages in the world and has received considerable attention regarding health risks and benefits. We conducted a genome-wide (GW) meta-analysis of predominately regular-type coffee consumption (cups per day) among up to 91,462 coffee consumers of European ancestry with top single-nucleotide polymorphisms (SNPs) followed-up in ~30 062 and 7964 coffee consumers of European and African-American ancestry, respectively. Studies from both stages were combined in a trans-ethnic meta-analysis. Confirmed loci were examined for putative functional and biological relevance. Eight loci, including six novel loci, met GW significance (log10Bayes factor (BF)>5.64) with per-allele effect sizes of 0.03-0.14 cups per day. Six are located in or near genes potentially involved in pharmacokinetics (ABCG2, AHR, POR and CYP1A2) and pharmacodynamics (BDNF and SLC6A4) of caffeine. Two map to GCKR and MLXIPL genes related to metabolic traits but lacking known roles in coffee consumption. Enhancer and promoter histone marks populate the regions of many confirmed loci and several potential regulatory SNPs are highly correlated with the lead SNP of each. SNP alleles near GCKR, MLXIPL, BDNF and CYP1A2 that were associated with higher coffee consumption have previously been associated with smoking initiation, higher adiposity and fasting insulin and glucose but lower blood pressure and favorable lipid, inflammatory and liver enzyme profiles (P<5 × 10(-8)).Our genetic findings among European and African-American adults reinforce the role of caffeine in mediating habitual coffee consumption and may point to molecular mechanisms underlying inter-individual variability in pharmacological and health effects of coffee.

Lack of gene-diuretic interactions on the risk of incident gout: the Nurses' Health Study and Health Professionals Follow-up Study

BACKGROUND

Diuretic-induced gout might occur only among those with a genetic predisposition to hyperuricaemia, as suggested by a recent study with 108 self-reported gout cases.

METHODS

We examined the role of urate genes on the risk of diuretic-induced incident gout in 6850 women from the Nurses' Health Study (NHS) and in 4223 men from the Health Professionals Follow-up Study (HPFS). Two published genetic risk scores (GRSs) were calculated using urate-associated single-nucleotide polymorphisms for 8 (GRS8) and 29 genes (GRS29).

RESULTS

Our analyses included 727 and 354 confirmed incident gout cases in HPFS and NHS, respectively. The multivariate relative risk (RR) for diuretic use was 2.20 and 1.69 among those with GRS8 < and ≥ the median (p for interaction=0.27). The corresponding RRs using GRS29 were 2.19 and 1.88 (p for interaction=0.40). The lack of interaction persisted in NHS (all p values >0.20) and in our analyses limited to those with hypertension in both cohorts. SLC22A11 (OAT4) showed a significant interaction only among women but in the opposite direction to the recent study.

CONCLUSIONS

In these large prospective studies, individuals with a genetic predisposition for hyperuricaemia are not at a higher risk of developing diuretic-induced gout than those without.

Medical management of kidney stones: AUA guideline

PURPOSE

The purpose of this guideline is to provide a clinical framework for the diagnosis, prevention and follow-up of adult patients with kidney stones based on the best available published literature.

MATERIALS AND METHODS

The primary source of evidence for this guideline was the systematic review conducted by the Agency for Healthcare Research and Quality on recurrent nephrolithiasis in adults. To augment and broaden the body of evidence in the AHRQ report, the AUA conducted supplementary searches for articles published from 2007 through 2012 that were systematically reviewed using a methodology developed a priori. In total, these sources yielded 46 studies that were used to form evidence-based guideline statements. In the absence of sufficient evidence, additional statements were developed as Clinical Principles and Expert Opinions.

RESULTS

Guideline statements were created to inform clinicians regarding the use of a screening evaluation for first-time and recurrent stone formers, the appropriate initiation of a metabolic evaluation in select patients and recommendations for the initiation and follow-up of medication and/or dietary measures in specific patients.

CONCLUSIONS

A variety of medications and dietary measures have been evaluated with greater or less rigor for their efficacy in reducing recurrence rates in stone formers. The guideline statements offered in this document provide a simple, evidence-based approach to identify high-risk or interested stone-forming patients for whom medical and dietary therapy based on metabolic testing and close follow-up is likely to be effective in reducing stone recurrence.

Gene × physical activity interactions in obesity: combined analysis of 111,421 individuals of European ancestry

Numerous obesity loci have been identified using genome-wide association studies. A UK study indicated that physical activity may attenuate the cumulative effect of 12 of these loci, but replication studies are lacking. Therefore, we tested whether the aggregate effect of these loci is diminished in adults of European ancestry reporting high levels of physical activity. Twelve obesity-susceptibility loci were genotyped or imputed in 111,421 participants. A genetic risk score (GRS) was calculated by summing the BMI-associated alleles of each genetic variant. Physical activity was assessed using self-administered questionnaires. Multiplicative interactions between the GRS and physical activity on BMI were tested in linear and logistic regression models in each cohort, with adjustment for age, age², sex, study center (for multicenter studies), and the marginal terms for physical activity and the GRS. These results were combined using meta-analysis weighted by cohort sample size. The meta-analysis yielded a statistically significant GRS × physical activity interaction effect estimate (P_interaction = 0.015). However, a statistically significant interaction effect was only apparent in North American cohorts (n = 39,810, P_interaction = 0.014 vs. n = 71,611, P_interaction = 0.275 for Europeans). In secondary analyses, both the FTO rs1121980 (P_interaction = 0.003) and the SEC16B rs10913469 (P_interaction = 0.025) variants showed evidence of SNP × physical activity interactions. This meta-analysis of 111,421 individuals provides further support for an interaction between physical activity and a GRS in obesity disposition, although these findings hinge on the inclusion of cohorts from North America, indicating that these results are either population-specific or non-causal.

We undertook analyses in 111,421 adults of European descent to examine whether physical activity diminishes the genetic risk of obesity predisposed by 12 single nucleotide polymorphisms, as previously reported in a study of 20,000 UK adults (Li et al, PLoS Med. 2010). Although the study by Li et al is widely cited, the original report has not been replicated to our knowledge. Therefore, we sought to confirm or refute the original study's findings in a combined analysis of 111,421 adults. Our analyses yielded a statistically significant interaction effect (P_interaction = 0.015), confirming the original study's results; we also identified an interaction between the FTO locus and physical activity (P_interaction = 0.003), verifying previous analyses (Kilpelainen et al, PLoS Med., 2010), and we detected a novel interaction between the SEC16B locus and physical activity (P_interaction = 0.025). We also examined the power constraints of interaction analyses, thereby demonstrating that sources of within- and between-study heterogeneity and the manner in which data are treated can inhibit the detection of interaction effects in meta-analyses that combine many cohorts with varying characteristics. This suggests that combining many small studies that have measured environmental exposures differently may be relatively inefficient for the detection of gene × environment interactions.

Abstract 153: Hypothyroidism and hyperthyroidism in relation to endometrial cancer: A prospective study

Background

Thyroid hormones may be involved in tumorigenesis and metastasis in hormone sensitive cancers. Thyroid hormones strongly influence the menstrual cycle, implantation and fertility, suggesting that thyroid hormones also could play a role in the development of endometrial cancer (EC), which is hormone-sensitive. No prospective studies have examined this association.

Methods

We prospectively evaluated the association between self-reported physician-diagnosed hypothyroidism and hyperthyroidism in the Nurses’ Health Study (NHS) from 1976 - 2010. Reports of thyroid dysfunction were based on self-report on biennial follow-up questionnaires, and have shown high validity when compared to medical records. Incident EC cases were confirmed with medical, pathology and death records. Multivariate rate ratios (RRs) for endometrial cancer were calculated, adjusting for major EC risk factors (i.e., body mass index, smoking, parity, age at last birth, oral contraceptive use, family history, age at menarche, age at menopause, postmenopausal hormone use, type 2 diabetes, and height).

Results

During 34 years of follow-up in NHS, we documented 917 cases of incident EC. Compared to those without any reported thyroid dysfunction, the multivariable RR for hypothyroidism was 0.99 (95% CI, 0.75-1.30) and the null associations were consistent across categories of time since hypothyroidism diagnosis. The multivariable RR for hyperthyroidism was 1.38 (95% CI 0.79 - 2.41). An association was observed with longer time since hyperthyroidism diagnosis (median time since hyperthyroidism diagnosis was 6 years in NHS); the RR for EC associated with 6+ years since hyperthyroidism diagnosis was 2.08 (95% CI, 1.02, 4.23).

Conclusions

Overall self-reported hypothyroidism and hyperthyroidism were not associated with risk of EC; however, longer time since hyperthyroidism diagnosis may be associated with an increased risk of EC. Due to the overall small number of cases with hyperthyroidism, on-going analyses will incorporate results from the Nurses’ Health Study II to increase power for these analyses.

Citation Format: Angela Kueck, Jae Hee Kang, Richard Stevens, Gary Curhan, Erik Alexander, Bernard Rosner, Immaculata DeVivo, Shelley Tworoger. Hypothyroidism and hyperthyroidism in relation to endometrial cancer: A prospective study. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 153. doi:10.1158/1538-7445.AM2013-153

Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders

Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate-increasing and heart rate-decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets.

A genome-wide association study of depressive symptoms

BACKGROUND

Depression is a heritable trait that exists on a continuum of varying severity and duration. Yet, the search for genetic variants associated with depression has had few successes. We exploit the entire continuum of depression to find common variants for depressive symptoms.

METHODS

In this genome-wide association study, we combined the results of 17 population-based studies assessing depressive symptoms with the Center for Epidemiological Studies Depression Scale. Replication of the independent top hits (p<1×10(-5)) was performed in five studies assessing depressive symptoms with other instruments. In addition, we performed a combined meta-analysis of all 22 discovery and replication studies.

RESULTS

The discovery sample comprised 34,549 individuals (mean age of 66.5) and no loci reached genome-wide significance (lowest p = 1.05×10(-7)). Seven independent single nucleotide polymorphisms were considered for replication. In the replication set (n = 16,709), we found suggestive association of one single nucleotide polymorphism with depressive symptoms (rs161645, 5q21, p = 9.19×10(-3)). This 5q21 region reached genome-wide significance (p = 4.78×10(-8)) in the overall meta-analysis combining discovery and replication studies (n = 51,258).

CONCLUSIONS

The results suggest that only a large sample comprising more than 50,000 subjects may be sufficiently powered to detect genes for depressive symptoms.

Genome-wide association analyses identify 18 new loci associated with serum urate concentrations

Elevated serum urate concentrations can cause gout, a prevalent and painful inflammatory arthritis. By combining data from >140,000 individuals of European ancestry within the Global Urate Genetics Consortium (GUGC), we identified and replicated 28 genome-wide significant loci in association with serum urate concentrations (18 new regions in or near TRIM46, INHBB, SFMBT1, TMEM171, VEGFA, BAZ1B, PRKAG2, STC1, HNF4G, A1CF, ATXN2, UBE2Q2, IGF1R, NFAT5, MAF, HLF, ACVR1B-ACVRL1 and B3GNT4). Associations for many of the loci were of similar magnitude in individuals of non-European ancestry. We further characterized these loci for associations with gout, transcript expression and the fractional excretion of urate. Network analyses implicate the inhibins-activins signaling pathways and glucose metabolism in systemic urate control. New candidate genes for serum urate concentration highlight the importance of metabolic control of urate production and excretion, which may have implications for the treatment and prevention of gout.

Association of sweetened beverage intake with incident hypertension

BACKGROUND

Consumption of sugar-sweetened beverages (SSBs) is associated with an increased risk of hypertension in cross-sectional studies. However, prospective data are limited.

OBJECTIVE

To examine the associations between SSBs and artificially sweetened beverages (ASBs) with incident hypertension.

DESIGN AND SETTING

Prospective analysis using Cox proportional hazards regression to examine the association between SSBs and ASBs with incident hypertension in three large, prospective cohorts, the Nurses' Health Studies I (n = 88,540 women) and II (n = 97,991 women) and the Health Professionals' Follow-Up Study (n = 37,360 men).

MEASUREMENTS

Adjusted hazard ratios for incident clinically diagnosed hypertension.

RESULTS

Higher SSB and ASB intake was associated with an increased risk of developing hypertension in all three cohorts. In a pooled analysis, participants who consumed at least one SSB daily had an adjusted HR for incident hypertension of 1.13 (95 % CI, 1.09-1.17) compared with those who did not consume SSBs; for persons who drank at least one ASB daily, the adjusted HR was 1.14 (95 % CI, 1.09-1.18). The association between sweetened beverage intake and hypertension was stronger for carbonated beverages versus non-carbonated beverages, and for cola-containing versus non-cola beverages in the NHS I and NHS II cohorts only. Higher fructose intake from SSBs as a percentage of daily calories was associated with increased hypertension risk in NHS I and NHS II (p-trend = 0.001 in both groups), while higher fructose intake from sources other than SSBs was associated with a decrease in hypertension risk in NHS II participants (p-trend = 0.006).

LIMITATIONS

Residual confounding factors may interfere with the interpretation of results.

CONCLUSIONS

SSBs and ASBs are independently associated with an increased risk of incident hypertension after controlling for multiple potential confounders. These associations may be mediated by factors common to both SSBs and ASBs (e.g., carbonation or cola), but are unlikely to be due to fructose.

Independent association of serum retinol and β-carotene levels with hyperuricemia: A national population study

OBJECTIVE

Uses of synthetic vitamin A derivatives (e.g., isotretinoin used for severe acne) and high doses of preformed vitamin A have been implicated in the pathogenesis of hyperuricemia and gout, whereas a trial reported that β-carotene may lower serum uric acid (UA) levels. We evaluated the potential population impact of these factors on serum UA in a nationally representative sample of US adults.

METHODS

Using data from 14,349 participants ages ≥20 years in the Third National Health and Nutrition Examination Survey (1988-1994), we examined the relationship between serum retinol, β-carotene, and UA levels using weighted linear regression. Additionally, we examined the relationship with hyperuricemia using weighted logistic regression.

RESULTS

Serum UA levels increased linearly with increasing serum retinol levels, whereas serum UA levels decreased with increasing serum β-carotene levels. After adjusting for age, sex, dietary factors, and other potential confounders, the serum UA level differences from the bottom (referent) to the top quintiles of serum retinol levels were 0, 0.16, 0.32, 0.43, and 0.71 mg/dl (P for trend <0.001), and for β-carotene were 0, -0.15, -0.29, -0.27, and -0.40 mg/dl (P for trend <0.001), respectively. Similarly, the multivariate odds ratios of hyperuricemia from the bottom (referent) to top quintiles of serum retinol levels were 1.00, 1.30, 1.83, 2.09, and 3.22 (P for trend <0.001) and for β-carotene were 1.00, 0.85, 0.68, 0.73, and 0.54 (P for trend <0.001), respectively. The graded associations persisted across subgroups according to cross-classification by both serum retinol and β-carotene levels.

CONCLUSION

These nationally representative data raise concerns that vitamin A supplementation and food fortification may contribute to the high frequency of hyperuricemia in the US population, whereas β-carotene intake may be beneficial against hyperuricemia. The use of β-carotene as a novel preventive treatment for gout deserves further investigation.

Duration of lactation and incidence of maternal hypertension: a longitudinal cohort study

Never or curtailed lactation has been associated with an increased risk for incident hypertension, but the effect of exclusive breastfeeding is unknown. The authors conducted an observational cohort study of 55,636 parous women in the US Nurses' Health Study II. From 1991 to 2005, participants reported 8,861 cases of incident hypertension during 660,880 person-years of follow-up. Never or curtailed lactation was associated with an increased risk of incident hypertension. Compared with women who breastfed their first child for ≥12 months, women who did not breastfeed were more likely to develop hypertension (hazard ratio (HR) = 1.27, 95% confidence interval (CI): 1.18, 1.36), adjusting for family history and lifestyle covariates. Women who never breastfed were more likely to develop hypertension than women who exclusively breastfed their first child for ≥6 months (HR = 1.29, 95% CI: 1.20, 1.40). The authors found similar results for women who had never breastfed compared with those who had breastfed each child for an average of ≥12 months (HR = 1.22, 95% CI: 1.13, 1.32). In conclusion, never or curtailed lactation was associated with an increased risk of incident maternal hypertension, compared with the recommended ≥6 months of exclusive or ≥12 months of total lactation per child, in a large cohort of parous women.