US National Health and Nutrition Examination Survey Arthritis Initiatives, Methodologies and Data

Systemic inflammatory biomarkers are novel predictors of all-cause and cardiovascular mortality in individuals with osteoarthritis: a prospective cohort study using data from the NHANES

BACKGROUND

Chronic inflammation may contribute to increased mortality risk in individuals with osteoarthritis (OA), but research on the prognostic value of inflammatory biomarkers is limited. We aimed to evaluate the associations of the systemic immune-inflammation index (SII) and systemic inflammation response index (SIRI) with all-cause and cardiovascular mortality among US adults with OA.

METHODS

This cohort study included 3545 adults with OA aged ≥ 20 years from the National Health and Nutrition Examination Survey 1999-2020. The SII and SIRI were calculated using complete blood cell count data. Participants were categorized as having a higher or lower SII and SIRI using cutoff points derived by the maximally selected rank statistics method. Cox proportional hazards models, Fine-Gray competing risk regression models and time-dependent receiver operating characteristic (ROC) analysis were used to evaluate the associations between the SII/SIRI and mortality in OA patients.

RESULTS

Over a median follow-up of 5.08 (3.42-9.92) years, 636 (17.94%) deaths occurred, including 149 (4.20%) cardiovascular deaths. According to multivariable-adjusted models involving demographic, socioeconomic, and health factors, OA patients with a higher SII had a twofold greater risk of all-cause mortality than patients with a lower SII (HR 2.01; 95% CI: 1.50-2.68). Similarly, a higher SIRI was associated with an 86% increased risk of all-cause mortality relative to a lower SIRI (HR 1.86; 95% CI: 1.46-2.38). Similar to the trend found with all-cause mortality, patients with an elevated SII and SIRI had a 88% and 67% increased risk of cardiovascular mortality, respectively, compared to patients with a lower SII (HR 1.88; 95% CI: 1.16-3.03) and SIRI (HR 1.67; 95% CI: 1.14-2.44). Time-dependent ROC curves showed that both the SII and SIRI have moderate and valid performance in predicting short- and long-term mortality in patients with OA.

CONCLUSIONS

Higher SII and SIRI values were associated with greater all-cause and cardiovascular mortality among US adults with OA.

The association between waist-to-height ratio and cognitive function in older adults

OBJECTIVES

The waist-to-height ratio (WHtR) is a simple, practical, and effective tool used to assess central obesity. Despite its usefulness, few studies have investigated the association between WHtR and cognitive function among older adults in the United States. This study aims to investigate the associations between WHtR and cognitive function.

METHODS

The study sample comprised adults who participated in the National Health and Nutrition Examination Survey (NHANES) between 2011 and 2014. WHtR was calculated from measured waist circumference and height. Cognitive function was assessed using the digit symbol substitution test. A weighted multiple linear regression analysis was performed to evaluate the association between WHtR and cognitive function, with smooth curve fitting applied to detect non-linearities.

RESULTS

Our analysis included 1709 participants over the age of 65. After adjusting for potential confounders, WHtR was found to have a negative association with cognitive function (β = -36.91, 95% CI: -54.54 to -19.29, P < 0.001). Subgroup analyzes stratified by sex and race showed that the negative correlation of WHtR with cognitive function remained in both men and women, as well as in non-Hispanic white and other races. Among women, the association between WHtR and cognitive function followed an inverted U-shaped curve, with an inflection point of 0.68.

CONCLUSION

This study provides evidence of a negative association between WHtR and cognitive function in older adults. These findings suggest that in advanced age, central obesity may have negative implications for cognitive function.

The interaction of perfluoroalkyl acids and a family history of diabetes on arthritis: analyses of 2011-2018 NHANES

Whether a family history of diabetes (FHD) and exposure to perfluoroalkyl acids (PFAAs) are correlated with an increased risk of developing arthritis remains unclear. This cross-sectional study was conducted to explore the correlations between FHD or exposure to PFAAs and arthritis as well as their interaction using the National Health and Nutrition Examination Survey (NHANES). In total, 6,194 participants aged ≥ 20 years from the 2011-2018 NHANES were enrolled. PFAAs are a cluster of synthetic chemicals, including perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorodecanoic acid (PFDA) and perfluorohexane sulfonic acid (PFHxS). FHD was evaluated using self-reported questionnaires. Arthritis was classified into three types, rheumatoid arthritis (RA), osteoarthritis (OA), and others, which were diagnosed using questionnaires. Generalized linear models (GLMs) were used to test the correlation between FHD and arthritis. To examine the joint effects of PFAAs and FHD on arthritis, interaction terms were applied in the GLM. Arthritis incidence was 26.7% among all participants. FHD was associated with both RA [OR = 1.70 (95% CI: 1.15-2.50)] and other types of arthritis [OR = 1.62 (95% CI: 1.21-2.16)]. However, the relationship between FHD and OA was not significant after adjustment (P = 0.18). Interaction outcomes indicated that higher PFDA levels increased the association between FHD and arthritis. FHD is associated with an increased incidence of arthritis, which may be increased by PFDA. Given the heavy burden of arthritis, preventive measures for arthritis and reduction of PFAAs exposure for patients with FHD are required.

The saturation effect of 25(OH)D level on sleep duration for older people:The NHANES 2011-2018

This study aimed to investigate the potential relationship between vitamin D and sleep duration in older adults. The study utilized multivariate linear regression models to estimate the associations between serum 25(OH)D and sleep duration. In addition, a smooth curve fitting approach was used to identify any non-linear trends between the two variables. The study included 15,749 participants over the age of 60. The results showed a positive correlation between serum 25(OH)D levels and sleep duration in the fully-adjusted model. This correlation was observed in both males and females, as well as in non-Hispanic White and non-Hispanic Black participants. No significant interactions were found between serum 25(OH)D levels and the stratifying variables. The curve fitting analysis revealed a non-linear relationship between 25(OH)D and sleep duration, with a saturation point observed at a serum 25(OH)D level of 40.6 ng/mL. In conclusion, the findings suggest that there is a positive correlation between serum 25(OH)D levels and sleep duration, with a saturation effect observed. A positive correlation is evident when serum 25(OH)D falls below 40.6 ng/mL.

The Associations between Helicobacter Pylori immunoglobulin G seropositivity and body mass index in adults

OBJECTIVES

Inconsistent evidence currently exists regarding the associations between Helicobacter Pylori (H. pylori) infection and body mass index (BMI). The goal of the current study was to examine independent associations of H. pylori immunoglobulin G (IgG) seropositivity and BMI in a U.S.-based population sample.

METHODS

The US National Health and Nutrition Examination Survey (NHANES) with 2,576 subjects from 1999 to 2000 were analyzed. Using multivariate logistic regression models, associations between H. pylori IgG seropositivity and BMI were calculated after potential confounders were taken into account. Subgroup analyses were conducted furtherly stratified by sex, age, and race.

RESULTS

H. pylori IgG seropositivity was not associated with BMI in the general population (OR = 0.998; 95% CI = 0.977-1.019; P = 0.842). In the subgroup analyses stratified by race, a negative correction was found between the H. pylori IgG seropositivity and BMI among other races (OR = 0.873; 95% CI = 0.795-0.959; P = 0.004) except non-Hispanic white (OR = 1.006, 95% CI 0.966 to 1.048, P = 0.762), non-Hispanic black (OR = 1.021, 95% CI 0.979 to 1.065, P = 0.335), and Mexican American (OR = 1.010, 95% CI 0.966 to 1.055, P = 0.665).

CONCLUSIONS

In the general population, H. pylori IgG seropositivity is not associated with increased BMI, which provides a new perspective on obesity management.

Chronic neck pain is associated with increased mortality in individuals with osteoarthritis: results from the NHANES database prospective cohort study

BACKGROUND

Neck pain (NP) is a common symptom reported in the elderly. However, no study has examined the relationship between NP and osteoarthritis (OA) so far, and this study aimed to investigate the association of neck pain with the prevalence and mortality of OA.

METHODS

A total of 5965 participants were included in this cohort study based on the National Health and Nutrition Examination Survey data set of the USA (NHANES). Death outcomes follow-up information was ascertained by linkage to National Death Index (NDI). The association between NP and OA was studied by multi-various logistic regression models after adjusting for potential confounding factors. Cox proportional hazards models were used to elucidate the relationship between NP and all-cause mortality in OA patients.

RESULTS

Among all participants, 8.18% had osteoarthritis, and 5.92% suffered from neck pain. Neck pain was associated with osteoarthritis [1.932 (1.232, 3.028), p < 0.01], which still reminded significant after adjustments [2.519 (1.325, 4.788), p < 0.01] and stratified analysis by sex, race, and smoke status. In OA patients, chronic neck pain (over 1 year) was significantly associated with higher risks of all-cause mortality before [2.94 (1.61, 5.37), p < 0.01] and after adjustment [3.30 (1.23, 45.85), p < 0.05].

CONCLUSION

Neck pain was strongly associated with osteoarthritis. Moreover, chronic neck pain over 1 year significantly increased the mortality of OA patients. Our study demonstrates the need to screen osteoarthritis in the neck pain population and select a more appropriate treatment strategy promptly for those patients.

Effect of pulmonary function on bone mineral density in the United States: results from the NHANES 2007-2010 study

The relationship between pulmonary function (PF) and bone mineral density (BMD) remains controversial. In the US population, we found a positive association between PF and BMD. Mixed variables such as age, gender, and race may influence this association.

INTRODUCTION

Based on the data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2010, this study explored whether there is a correlation between PF (1st second forceful expiratory volume as a percentage of expected value (FEV1(% predicted)), (one-second rate (FEV1/FVC)), and bone mineral density.

METHODS

We evaluated the relationship between PF and BMD in 6327 NHANES subjects (mean age 44.51 ± 15.64 years) from 2007 to 2010. The bone mineral density of the whole femur was measured by dual-energy X-ray absorptiometry (DXA). After adjusting for a wide range of confounders, we examined the relationship between PF and total femur BMD using a multiple linear regression model.

RESULTS

Correction of race, age, alcohol consumption, body mass index (BMI), height, poor income ratio (PIR), total protein, serum calcium, serum uric acid, cholesterol, serum phosphorus, blood urea nitrogen, FEV1(% predicted), and femur BMD were positively correlated (β = 0.032, 95% CI: 0.010-0.054, P = 0.004). FEV1/FVC was positively correlated with spine BMD (β = 0.275 95%CI: 0.102-0.448, P = 0.002).

CONCLUSIONS

Our study shows that PF is positively associated with BMD in the US population. A variety of factors such as race and age influence this relationship. the relationship between PF and BMD needs to be further investigated, including specific regulatory mechanisms and confounding factors.

Association of smoking and osteoarthritis in US (NHANES 1999-2018)

Little is currently known about the effect of smoking on osteoarthritis (OA). This study aimed to investigate the relationship between smoking and OA in the United States (US) general population. Cross-sectional study. Level of evidence, 3. 40,201 eligible participants from the National Health and Nutrition Examination Survey 1999-2018 were included and divided into OA and non-arthritis groups. Participants demographics and characteristics were compared between the two groups. Then the participants were divided into non-smokers, former smokers, and current smokers based on their smoking status, also demographics and characteristics among the three groups were compared. Multivariable logistic regression was used to determine the relationship between smoking and OA. The current and former smoking rate in the OA group (53.0%) was significantly higher than that in the non-arthritis group (42.5%; p < 0.001). Multivariable regression analysis including body mass index (BMI), age, sex, race, education level, hypertension, diabetes, asthma and cardiovascular disease showed that smoking was an association for OA. This large national study highlights a positive association between smoking and OA prevalence in the general US population. It is necessary to further study the relationship between smoking and OA in order to determine the specific mechanism of smoking on OA.

Association between Serum 25-Hydroxyvitamin D and Abdominal Aortic Calcification: A Large Cross-Sectional Study

In the American population, the relationship between the standardized serum 25-hydroxyvitamin D (25(OH)D) concentration and the risk of abdominal aortic calcification (AAC) is unclear. The purpose of our study was to investigate the relationship between serum 25(OH)D concentration and AAC risk. Participants from the National Health and Nutrition Examination Survey (NHANES) between 2013 and 2014 were analyzed cross sectionally. An analysis of the relationship between serum 25(OH)D concentration and incident AAC and severe AAC (SAAC) was based on the restricted cubic spline (RCS) and multivariable logistic regression model. In addition, generalized additive models with smooth functions were used to evaluate the relationship between serum 25(OH)D concentration and the degree of AAC. Finally, a subgroup analysis was conducted. There were a total of 3,040 individuals in our study. The serum 25(OH)D concentration was divided into quartiles (Q1: 9.37-50.5 nmol/L; Q2: 50.6-67.2 nmol/L; Q3: 67.3-85.8 nmol/L; and Q4: 85.9-318.0 nmol/L); the lowest quartile served as the reference group (Q1). After adjusting for known confounding variables, compared with the lowest quartile (Q1) of serum 25(OH)D concentration, the odds ratios with 95% confidence intervals for AAC and SAAC across the quartiles (Q2, Q3, and Q4) were (1.042 (0.812, 1.338), 0.863 (0.668, 1.115), and 1.022 (0.787, 1.327)) and (1.48 (0.87, 2.52), 1.70 (1.01, 2.92), and 2.13 (1.19, 3.86)), respectively. As shown by the RCS plot, the serum 25(OH)D concentration was associated with the risk of AAC/SAAC in a U-shaped pattern (P for nonlinearity <0.05). In addition, the degree of AAC decreased at first and then increased as the serum 25(OH)D concentration increased. In conclusion, a U-shaped relationship existed between serum 25(OH)D concentration and the risk of AAC and SAAC. Consequently, the risk of AAC and SAAC may be mitigated with regular monitoring and vitamin D supplementation.

Differential influences of serum vitamin C on blood pressure based on age and sex in normotensive individuals

Aim

Hypertension is among the most prevalent chronic diseases with diverse etiology, affecting over 1 billion people globally. In numerous studies, vitamin C inversely correlated with blood pressure and was suspected to have antihypertensive properties. Currently, there is conflicting evidence regarding the relationship between vitamin C and blood pressure, with most studies being conducted on hypertensive subjects. The principal objective of this project was to investigate the relationship between vitamin C and blood pressure in normotensive adult subjects.

Methods

A total of 2,533 individuals aged 20 years and above were enrolled in the present study from the National Health and Nutrition Examination Survey (NHANES) 2017-2018. Outcome variables were systolic blood pressure (SBP) and diastolic blood pressure (DBP). Serum vitamin C was regarded as an independent variable. EmpowerStats software and R (version 3.4.3) were used to examine the association between vitamin C and SBP or DBP.

Results

Vitamin C was reversely correlated with both SBP (β = −0.02, 95% CI: −0.03 to −0.00, p = 0.0306) and DBP (β = −0.02, 95% CI: −0.04 to −0.01, p = &lt;0.0011) after adjusting all covariates. This reverse relationship may be affected by a number of factors, including a person’s gender, age, race, and ethnicity. A U-shaped association between vitamin C and SBP in females and an inverted one between vitamin C and DBP in males were detected, respectively. We further calculated the inflection points at 90.3 μmol/L for females and 40 μmol/L for males. It is somewhat surprising that a reverse U-shaped distribution between vitamin C and SBP and DBP in people over 50 was detected, and the point of inflection of vitamin C were all located at 40 μmol/L.

Conclusion

Vitamin C was negatively correlated with both SBP and DBP in this cross-sectional analysis. However, a U-shaped relationship and an inverted one were also observed in certain people, which implied that, though vitamin C is considered a vital antioxidant, maintaining vitamin C at appropriate levels may be beneficial according to different populations.

Axial Pain and Arthritis in Diagnosed Inflammatory Bowel Disease: US National Health and Nutrition Examination Survey Data

Objective

To estimate the nationally representative prevalence of chronic axial pain, inflammatory back pain (IBP), axial spondyloarthritis (axSpA), and peripheral arthritis in persons diagnosed with inflammatory bowel disease (IBD).

Patients and Methods

US National Health and Nutrition Examination Survey (NHANES) data from the 1976-1980 and 2009-2010 survey cycles.

Results

In NHANES 1976-1980, the chronic axial pain prevalence in participants with diagnosed ulcerative colitis (UC) was 19.5% vs 7.2% in the general population (P<.01). Neck or upper back, lower back, and Amor criteria-based axial pain were also significantly increased (11.2%, 14.5%, and 13.0%, respectively, vs 3%-5% in the general population (P<.01). In those with diagnosed UC, 40% had axial pain onset at an age older than 45 years; 30.2% reported peripheral arthralgias, and 12.2% reported peripheral arthritis. Arthritis findings on examination were uncommon. In NHANES 2009-2010, axial pain in those diagnosed with IBD had similar patterns.

Conclusion

Despite high rates of chronic axial pain in those with IBD, few cases met the IBP and axSpA classification criteria. This apparent discrepancy is unexplained. However, in IBD, axial pain onset at an age older than 45 years is common; and these may not meet IBP and axSpA age criteria. Also, neck pain was increased in those with IBD but is not included in most IBP and axSpA criteria. Peripheral arthralgias and chronic arthritis symptoms were common, but examination findings were not, suggesting that tenosynovitis or enthesitis is more likely than frank arthritis to occur in patients with UC.

Low dose aspirin associated with greater bone mineral density in older adults

The use of low-dose aspirin in older adults is increasing as is the prevalence of osteoporosis. Aspirin has been shown in numerous studies to affect bone metabolism. However, there is no clear link between low-dose aspirin use and bone mineral density (BMD). This study examined differences in bone mineral density between low-dose aspirin users and non-aspirin users in adults aged 50-80 years. We conducted a cross-sectional study of 15,560 participants who participated in the National Health and Nutrition Examination Survey (NHANES) 2017-March 2020. We used a multivariate logistic regression model to evaluate the relationship between low-dose aspirin and femoral neck BMD, femoral total BMD, intertrochanteric BMD, and the first lumbar vertebra BMD (L1 BMD) in patients aged 50 to 80 years. A total of 1208 (Group 1: femoral neck BMD, total femur BMD, and intertrochanter BMD) and 1228 (Group 2: L1 BMD) adults were included in this study. In both group 1 and group 2, BMD was higher in the low-dose aspirin group than in the non-aspirin group (Total femur BMD β = 0.019, 95% CI 0.004-0.034; Femoral neck BMD β = 0.017, 95% CI 0.002-0.032; Intertrochanter BMD β = 0.025, 95% CI 0.007-0.043; L1 BMD β = 0.026, 95% CI 0.006-0.046). In subgroup analyses stratified by gender, this positive association existed in both gender after adjusting for confounders. On subgroup analyses stratified by age, this positive association existed in three different age groups after adjusting for confounders. To test whether the effect of low-dose aspirin on BMD was affected by gender and age, the interaction P value was greater than 0.05. These findings from a human study looking into the relationship between low-dose aspirin use and BMD suggest that regular low-dose aspirin may be associated with a higher BMD. The association between low-dose aspirin and BMD did not differ by age group or gender.

Association Between History of Gestational Diabetes Mellitus and the Risk of Arthritis in Women

Objective

The association between gestational diabetes mellitus (GDM) and the risk of arthritis has not been reported. GDM increases the risk of long-term complications including diabetes and metabolic syndrome that are positively associated with the risk of arthritis. This study aimed to explore the association between GDM and the risk of arthritis.

Methods

Women (age ≥ 20 years) who had delivered at least one live birth were included from the 2007 to 2018 National Health and Nutrition Examination Survey cohort (N = 11,997). Patients who had a history of GDM and arthritis were identified by in-home interview. Subgroup analyses were conducted by arthritis types and status of obesity, current diabetes, metabolic syndrome, smoking, alcohol drinking, and physical activity.

Results

GDM was associated with increased odds of arthritis [multivariable-adjusted odds ratio (95% confidence interval): 1.31 (1.06–1.62)], and the result was similar in sensitivity analysis with further adjustment for metabolic syndrome [1.30 (1.05–1.60)]. In subgroup analyses, GDM was associated with increased odds of osteoarthritis [1.47 (1.05–2.06)], while no association was observed with rheumatoid arthritis [1.04 (0.69–1.57)] and other types [1.26 (0.94–1.68)]. GDM was associated with increased odds of arthritis in women without metabolic syndrome [1.34 (1.00–1.78)] and diabetes [1.35 (1.03–1.76)], in obese individuals [1.64 (1.24–2.16)], current/former smokers [1.43 (1.05–1.95)], and current drinkers [1.76 (1.00–3.14)], and in individuals engaging in higher levels of physical activity [1.53 (1.06–2.20)].

Conclusions

GDM was associated with increased odds of arthritis, and the association was independent of type 2 diabetes and metabolic syndrome.

The gender-specific adverse association of polycyclic aromatic hydrocarbons on skeletal muscle mass and strength in the general adults and the possible mechanisms in experimental rats

Whether polycyclic aromatic hydrocarbons (PAHs) exposure is associated with muscle mass and muscle strength has been scantly investigated. The cross-sectional associations of urinary PAH metabolites with appendicular skeletal muscle mass and hand grip strength in adults were first investigated in the National Health and Nutrition Examination Survey (NHANES). Laboratory study was further carried out to examine the effect of PAHs on skeletal muscle mass and strength. 2742 and 2462 US adults were finally analyzed for muscle mass and muscle strength, respectively. In male participants, urinary PAH metabolites were found to show an inverse relationship with muscle mass and grip strength. In female participants, no significant relationship was found between urinary PAH metabolites with muscle mass or grip strength. In male Sprague-Dawley (SD) rats, administration of B [a]P induced muscle atrophy when compared with the control. However, muscle mass and strength were not significantly altered in female rats. The variations in muscle morphology parameters were accompanied by significant decrease in plasma testosterone levels in the B [a]P-treated male rats. Testosterone co-treatment significantly mitigated B [a]P mediated damages in skeletal muscle in male rats. The results of the present study indicate that there may be a gender-specific causal relationship between the PAHs and muscle atrophy.

The relationship between high-density lipoprotein cholesterol (HDL-C) and glycosylated hemoglobin in diabetic patients aged 20 or above: a cross-sectional study

AIM

The incidence rate of diabetes is increasing year by year, seriously threatening human health. As a predictor of glycemic control, glycated hemoglobin is reported to be related to various complications and prognoses of diabetes. Besides, HDL-C dyslipidemia is a component of metabolic syndrome and may be related to various cardiovascular and cerebrovascular diseases. The principal objective of this project was to investigate the relationship between HDL-C and glycosylated hemoglobin in adult diabetic patients.

METHODS

A total of 3171 adult diabetic patients aged 20 years and above were included in the present study from the National Health and Nutrition Examination Survey (NHANES). HDL-C and glycosylated hemoglobin were regarded as independent and dependent variables, respectively. EmpowerStats software and R (version 3.4.3) were used to examine the association between HDL-C and glycosylated hemoglobin.

RESULTS

HDL-C was inversely associated with glycohemoglobin after adjusting for other covariates (β = - 0.004, 95% CI:- 0.008 to - 0.000, p = 0.044). Race/ethnicity and age were considered the most prominent interactive factors that affect the relationship between HDL and glycosylated hemoglobin by the interaction analysis. A U-shaped association was detected between HDL-C and glycosylated hemoglobin for people of other race/ethnicity or aged 60 and above, which had an inflection point of HDL-C at 60 mg/dL. In contrast, we observed an inverted U-shaped distribution between HDL-C and glycosylated hemoglobin in people under 40 with point of inflection located at 60 mg/dL as well.

CONCLUSIONS

HDL-C in diabetic patients is inversely associated with glycosylated hemoglobin and may be relevant to glycemic control. However, a U-shaped relationship was also observed in a certain kind of people, which implied that, though HDL-C is considered as metabolism and anti-atherogenic property, for diabetics, it is not the higher, the better.

Correlation of osteoarthritis or rheumatoid arthritis with bone mineral density in adults aged 20-59 years

Background

It is reported that osteoporosis commonly occurs among patients with rheumatoid arthritis (RA), whereas the association between osteoporosis and osteoarthritis (OA) remains controversial. Our aim in this study was to investigate the association between BMD, as a marker of osteoporosis, and OA and RA among adults 20−59 years of age, using a population-based sample from the National Health and Nutrition Examination Survey (NHANES).

Methods

Our analysis was based on the NHANES data collected between 2011 and 2018. Data regarding arthritis status and the type of arthritis (OA or RA) were obtained from questionnaires. Lumbar BMD was measured by dual-energy X-ray absorptiometry. The association between OA, RA, and lumbar BMD was evaluated using logistic regression models. Subgroup analyses, stratified by gender and race, were performed. The association between duration of arthritis and lumbar BMD was also investigated.

Results

A total of 11,094 adults were included in our study. Compared to the non-arthritis group, participants with OA had a higher lumbar BMD (β = 0.023, 95% CI 0.011–0.035), with no significant association between lumbar BMD and RA (β = 0.014, 95% CI − 0.003 to 0.031). On subgroup analyses stratified by gender, males with OA had a higher lumbar BMD compared to those without OA (β = 0.047, 95% CI 0.028–0.066). In females, OA was not associated with lumbar BMD (β = 0.007, 95% CI − 0.008 to 0.021). There was no association between lumbar BMD and RA in both males (β = 0.023, 95% CI − 0.003 to 0.048) and females (β = 0.008, 95% CI − 0.015 to 0.031). Duration of arthritis was not associated with lumbar BMD for both OA (β = − 0.0001, 95% CI − 0.0017 to 0.0015) and RA (β = 0.0006, 95% CI − 0.0012 to 0.0025).

Conclusions

Lumbar BMD was associated with OA but not with RA. While a higher lumbar BMD was associated with OA in males, but not in females. Our findings may improve our understanding between OA, RA, and bone health.

Population-based estimates of humoral autoimmunity from the U.S. National Health and Nutrition Examination Surveys, 1960-2014

Objective

Based on US National Health and Nutrition Examination Survey (NHANES) data, we attempted to provide an unbiased, population-based estimate of autoantibody prevalence overall and by age and sex.

Methods

US autoantibody prevalence estimates for detectable rheumatoid factor, anti-thyroglobulin, anti-thyroperoxidase, anti-transglutaminase, anti-endomysial, anti-GAD65, antinuclear autoantibodies, and autoantibodies to extractable nuclear antigens were estimated from the 1960–1962 National Health Examination Survey, NHANES III (1988–1994), and the NHANES 1999–2014 cross-sectional surveys. Survey design variables and sample weights were used to account for differential probabilities of selection within the complex survey design. Data analysis used SAS^TM and SUDAAN^™ software. US Census Bureau data were used to estimate the absolute numbers of persons with autoantibodies.

Results

NHANES III data show that the overall US prevalence of having a detectable serum autoantibody is substantial in adults, in both women and men. Thyroid autoantibodies were present in 18% of US adults (31 million persons) including 10% of younger adults and 25% of older persons. Overall autoantibody prevalences increased significantly with age: 32% of US adults 60+ years of age (12.8 million persons) had at least one of the four autoantibodies rheumatoid factor, anti-thyroglobulin, anti-thyroperoxidase, or anti-tissue transglutaminase. Older women had higher levels of autoantibodies, but this was a relative difference. Autoantibody prevalence in both sexes was substantial (women 39%; men 22%). Fourteen percent of adults 60+ years of age have multiple autoantibodies.

Conclusions

Autoantibodies are present in a significant fraction of the general population, especially in older adults and women relative to men. Although all known clinically significant autoantibodies were not analyzed, these data provide an important population perspective on the scope and magnitude of humoral autoimmunity in the US. This is vital for prevention efforts to reduce autoimmune disease and helps clarify the potential impact of autoimmunity on the general population.