Association Between Lifting Weights and Metabolic Syndrome among U.S. Adults: 1999-2004 National Health and Nutrition Examination Survey

ABSTRACT: Magyari, PM and Churilla, JR. Association between lifting weights and metabolic syndrome among U.S. adults: 1999-2004 National Health and Nutrition Examination Survey. J Strength Cond Res 26(11): 3113-3117, 2012-The purpose of this cross-sectional study was to determine the proportion of U.S. adults who participate in the resistance exercise modality of lifting weights (LWs) by demographic characteristics and to investigate the impact of LWs on the prevalence and risk of metabolic syndrome (MetS) in a national representative sample of U.S. adults. The sample (n = 5,618) in this cross-sectional study included adults aged ≥20 years who participated in the 1999-2004 National Health and Nutrition Examination Survey. Approximately twice as many men (11.2%; 95% confidence interval [CI] 9.5, 13.1) reported LWs as women did (6.3%; 95% CI 5.2, 7.6) with non-Hispanic Whites (9.6%; 95% CI 8.1, 11.4) reporting the highest levels and Mexican Americans reporting the lowest levels (5.6%; 95% CI 4.4, 7.2) of engaging in LWs. Additionally, higher levels of socioeconomic status were associated with greater levels of self-reported LWs. MetS prevalence was found to be significantly lower among U.S. adults reporting LWs (24.6%; 95% CI 19.3, 30.9) compared with adults not reporting LWs (37.3%; 95% CI 35.5, 39.2) with associated risk reductions of 58% (p < 0.001) and 37% (p < 0.01) in the unadjusted model and model adjusted for demographic variables, respectively. These findings suggest that LWs may play a role in reducing the prevalence and risk of MetS among U.S. adults. Therefore, exercise professionals should strongly encourage the activity of LWs among adults of all ages to promote metabolic health and focus programs designed to increase the adoption of LWs among the subgroups who report the lowest levels of LWs.     

Pulmonary Impairment in Tuberculosis Survivors: The Korean National Health and Nutrition Examination Survey 2008-2012

Objectives

Pulmonary tuberculosis (TB) can affect lung function, but studies regarding long-term follow-up in patients with no sequelae on chest X-ray (CXR) have not been performed. We evaluated lung functional impairment and persistent respiratory symptoms in those with prior pulmonary TB and those with prior pulmonary TB with no residual sequelae on CXR, and determined risk factors for airflow obstruction.

Methods

We used data from adults aged ≥ 40 years from the annual Korean National Health and Nutrition Examination Surveys conducted between 2008 and 2012. P values for comparisons were adjusted for age, sex, and smoking status.

Results

In total of 14,967 adults, 822 subjects (5.5%) had diagnosed and treated pulmonary TB (mean 29.0 years ago). The FVC% (84.9 vs. 92.6), FEV₁% (83.4 vs. 92.4), and FEV₁/FVC% (73.4 vs. 77.9) were significantly decreased in subjects with prior pulmonary TB compared to those without (p < 0.001, each). In 12,885 subjects with no sequalae on CXR, those with prior pulmonary TB (296, 2.3%) had significantly lower FEV₁% (90.9 vs. 93.4, p = 0.001) and FEV₁/FVC% (76.6 vs. 78.4, p < 0.001) than those without. Subjects with prior pulmonary TB as well as subjects with no sequalae on CXR were more likely to experience cough and physical activity limitations due to pulmonary symptoms than those without prior pulmonary TB (p < 0.001, each). In total subjects, prior pulmonary TB (OR, 2.314; 95% CI, 1.922–2.785), along with age, male, asthma, and smoking mount was risk factor for airflow obstruction. In subjects with prior pulmonary tuberculosis, inactive TB lesion on chest x-ray (OR, 2.300; 95% CI, 1.606–3.294) were risk factors of airflow obstruction.

Conclusion

In addition to subjects with inactive TB lesion on CXR, subjects with no sequelae on CXR can show impaired pulmonary function and respiratory symptoms. Prior TB is a risk factor for airflow obstruction and that the risk is more important when they have inactive lesions on chest X-ray. Hence, the patients with treated TB should need to have regular follow-up of lung function and stop smoking for early detection and prevention of the chronic airway disease.     

Association between misalignment of circadian rhythm and obesity in Korean men: Sixth Korea National Health and Nutrition Examination Survey

ABSTRACT

Background: The disruption of circadian rhythm has been found to associate with obesity in vivo and in vitro. Sleep duration, eating habits, total feeding time, and nightshift work can also affect circadian rhythms. This study investigated the association between misalignment of circadian rhythm and obesity in Korean men, using a cross-sectional database.

Methods: This study used data from the Korean National Health and Nutrition Examination Survey (KNHANES), whose study population was 3,658 men aged 18 to 60 years. General and abdominal obesity was defined as a body mass index (BMI) ≥ 25 kg/m² and waist circumference ≥ 90 cm, respectively. Circadian rhythm factors were determined with a self-report questionnaire and included breakfast frequency, sleep duration, and work time. Frequency of breakfast was divided into regular breakfast (five to seven times a week) and irregular breakfast (less than five times a week). Sleep duration was divided into less than 7 hours, 7–9 hours, and over 9 hours. Working time was defined as day/evening, night shift, and other type. The adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for general and abdominal obesity were calculated using multivariable logistic regression according to the number of factors that disturb the circadian rhythm.

Results: Participants with 1 (aOR 1.34, 95% Cl 1.10–1.61) and ≥2 (aOR 1.62, 95% Cl 1.29–2.05) factors disturbing circadian rhythms were associated with elevated risk for general obesity. Similarly, those with 1 (aOR 1.33, 95% Cl 1.09–1.63) and ≥2 (aOR 1.70, 95% Cl 1.32–2.20) factors had elevated risk for abdominal obesity.

Conclusions: Factors disturbing the circadian rhythm were associated with general and abdominal obesity. Additional studies are needed, and associations with metabolic diseases should be investigated.     

Assessment of chronic mercury exposure within the U.S. population, National Health and Nutrition Examination Survey, 1999–2006

The purpose of this study was to assess chronic mercury exposure within the US population. Time trends were analyzed for blood inorganic mercury (I-Hg) levels in 6,174 women, ages 18–49, in the NHANES, 1999–2006 data sets. Multivariate logistic regression distinguished a significant, direct correlation within the US population between I-Hg detection and years since the start of the survey (OR = 1.49, P < 0.001). Within this population, I-Hg detection rose sharply from 2% in 1999–2000 to 30% in 2005–2006. In addition, the population averaged mean I-Hg concentration rose significantly over that same period from 0.33 to 0.39 μ/L (Anova, P < 0.001). In a separate analysis, multivariate logistic regression indicated that I-Hg detection was significantly associated with age (OR = 1.02, P < 0.001). Furthermore, multivariate logistic regression revealed significant associations of both I-Hg detection and mean concentration with biomarkers for the main targets of mercury deposition and effect: the liver, immune system, and pituitary. This study provides compelling evidence that I-Hg deposition within the human body is a cumulative process, increasing with age and in the population over time, since 1999, as a result of chronic mercury exposure. Furthermore, our results indicate that I-Hg deposition is associated with the significant biological markers for main targets of exposure, deposition, and effect. Accumulation of focal I-Hg deposits within the human body due to chronic mercury exposure provides a mechanism which suggests a time dependent rise in the population risks for associated disease.     

Gender Difference in the Epidemiological Association between Metabolic Syndrome and Olfactory Dysfunction: The Korea National Health and Nutrition Examination Survey

Metabolic syndrome (MetS) is associated with a higher risk of morbidity and/or mortality for various chronic diseases. The aim of this study was to investigate the relationships of MetS and its components with olfactory dysfunction in a representative Korean population. We analyzed the data from the Korean National Health and Nutrition Examination Survey (2008–2010). A total of 11,609 adults who underwent otolaryngological examination were evaluated. The olfactory function was classified as normosmia or hyposmia by a self-report questionnaire according to the sense problems of smell during the past 3 months. MetS was diagnosed if a participant had at least three of the following: (1) WC ≥90 cm in men and ≥80 cm in women; (2) fasting blood sugar ≥ 100 mg/dL or medication use for elevated glucose; (3) fasting triglyceride ≥ 150 mg/dL or cholesterol-lowering medication use; (4) HDL-cholesterol <40 mg/dL in men and <50 mg/dL in women or cholesterol-lowering medication use; and (5) SBP ≥ 130 mmHg and/or DBP ≥ 85 mmHg or antihypertensive drug use for patients with a history of hypertension. The prevalence of olfactory dysfunction in the study population was 6.3%. The prevalence of olfactory dysfunction was significantly higher in older people with MetS than in those without MetS in both sexes (male, 42.0 ± 3.4% vs. 34.7 ± 0.9%, p = 0.0354; female, 46.2 ± 2.8% vs. 37.8 ± 0.8%, p = 0.0026). However, elevated waist circumference, elevated fasting glucose, elevated triglycerides, reduced HDL cholesterol, elevated blood pressure, severe stress, depressed mood, and suicidal ideation were significantly associated with olfactory dysfunction only in women. After controlling for confounders, olfactory dysfunction was significantly associated with MetS (odds ratio, 1.352; 95% confidence interval, 1.005–1.820) only in women. MetS are associated with olfactory dysfunction only in Korean women.     

Health Insurance Status as a Barrier to Ideal Cardiovascular Health for U.S. Adults: Data from the National Health and Nutrition Examination Survey (NHANES)

Background

Little is known about the association between cardiovascular (CV) health and health insurance status. We hypothesized that U.S. adults without health insurance coverage would have a lower likelihood of ideal cardiovascular health.

Methods and Results

Using National Health and Nutrition Examination Survey (NHANES) data from 2007–2010, we examined the relationship between health insurance status and ideal CV health in U.S. adults aged ≥19 years and <65 (N = 3304). Ideal CV health was defined by the American Heart Association (AHA) as the absence of clinically manifested CV disease and the simultaneous presence of 6–7 “ideal” CV health factors and behaviors. Logistic regression modeling was used to determine the relationship between health insurance status and the odds of ideal CV health. Of the U.S. adult population, 5.4% attained ideal CV health, and 23.5% were without health insurance coverage. Those without health insurance coverage were more likely to be young (p<0.0001), male (p<0.0001), non-white (p<0.0001), with less than a high school degree (p<0.0001), have a poverty-to-income ratio less than 1 (p<0.0001) and unemployed (p<0.0001) compared to those with coverage. Lack of health insurance coverage was associated with a lower likelihood of ideal CV health; however, this relationship was attenuated by socioeconomic status.

Conclusions

U.S. adults without health insurance coverage are less likely to have ideal CV health. Population-based strategies and interventions directed at the community-level may be one way to improve overall CV health and reach this at-risk group.     

Age-Related Association of Refractive Error with Intraocular Pressure in the Korea National Health and Nutrition Examination Survey

Background

To investigate the distribution of intraocular pressure (IOP) and refractive errors according to age group in a representative sample of non-glaucomatous Korean adults.

Methods

A total of 7,277 adults (≥19 years) who participated in the Korea National Health and Nutrition Examination Survey (KNHANES) from 2008 to 2011 underwent ophthalmic examination were divided into three groups according to age: the young- (19–39 years), middle- (40–59 years), and old- (≥60 years) age groups. Simple and multiple regression analyses between IOP and various parameters (including the refractive error) were conducted.

Results

The mean IOP of the total population was 14.0±0.1 mmHg [young: 13.9±0.1 mmHg; middle: 14.1±0.1 mmHg; old: 13.8±0.2 mmHg (P for trend = 0.085)]. Myopia and high myopia were more prevalent in the young- (70.8% and 16.1%, respectively), compared to the middle- (44.6% and 10.9%) and old- (8.9% and 2.2%) age groups. Univariate analysis in the total population showed that higher IOP was associated with myopic refractive error, the female gender, higher body mass index (BMI), diabetes, hypertension, and hypercholesterolemia (all P<0.05). In the young- and middle-age groups, higher IOP was associated with myopic refractive error, the female gender, higher BMI, hypercholesterolemia and diabetes (all P<0.05). In the old-age group, the association between IOP and refractive error was not significant (P = 0.828). In multiple linear regression analysis, similar significant relationships between the refractive error and IOP were found in the young- and middle-age groups (beta = −0.08 and −0.12; P = 0.002 and <0.001 for young- and middle-age group, respectively), but not in the old-age group (beta = 0.03; P = 0.728), after adjusting for age, gender, BMI, region of habitation, diabetes, hypertension, and hypercholesterolemia.

Conclusions

Myopic refractive error was an independent predictor of higher IOP in non- glaucomatous eyes, and the association between refractive error and IOP differed according to age.     

Tuberculosis Infection in the United States: Prevalence Estimates from the National Health and Nutrition Examination Survey, 2011-2012

Background

Reexamining the prevalence of persons infected with tuberculosis (TB) is important to determine trends over time. In 2011–2012 a TB component was included in the National Health and Nutrition Examination Survey (NHANES) to estimate the reservoir of persons infected with TB.

Methods

Civilian, noninstitutionalized U.S. population survey participants aged 6 years and older were interviewed regarding their TB history and eligibility for the tuberculin skin test (TST) and interferon gamma release assay (IGRA) blood test. Once eligibility was confirmed, both tests were conducted. Prevalence and numbers of TST positive (10 mm or greater), IGRA positive, and both TST and IGRA positive were calculated by adjusting for the complex survey design after applying corrections for item nonresponse and digit preference in TST induration measurements. To examine TST positivity over time, data from NHANES 1999–2000 were reanalyzed using the same statistical methods. The TST was performed using Tubersol, a commercially available purified protein derivative (PPD), rather than PPD-S, which was the antigen used in NHANES 1999–2000. Prior patient history of TB vaccination was not collected in this study nor were patients examined for the presence of a Bacillus of Calmette and Guerin (BCG) vaccine scar.

Results

For NHANES 2011–2012, TST and IGRA results were available for 6,128 (78.4%) and 7,107 (90.9%) eligible participants, respectively. There was no significant difference between the percentage of the U.S. population that was TST positive in 2011–2012 (4.7% [95% CI 3.4–6.3]; 13,276,000 persons) compared with 1999–2000 (4.3%; 3.5–5.3). In 2011–2012 the percentage that was IGRA positive was 5.0% (4.2–5.8) and double TST and IGRA positivity was 2.1% (1.5–2.8). The point estimate of IGRA positivity prevalence in foreign-born persons (15.9%; 13.5–18.7) was lower than for TST (20.5%; 16.1–25.8) in 2011–2012. The point estimate of IGRA positivity prevalence in U.S.-born persons (2.8%; 2.0–3.8) was higher than for TST (1.5%; 0.9–2.6).

Conclusions

No statistically significant decline in the overall estimated prevalence of TST positivity was detected from 1999–2000 to 2011–2012. The prevalence of TB infection, whether measured by TST or IGRA, remains lower among persons born in the United States compared with foreign-born persons.     

The Association between Chronic Kidney Disease and Diabetic Retinopathy: The Korea National Health and Nutrition Examination Survey 2008-2010

Purpose

To explore the relationship between chronic kidney disease and diabetic retinopathy in a representative population of Korean diabetic adults.

Methods

We analyzed data from the Korea National Health and Nutrition Examination Surveys (2008-2010). A total of 15,409 individuals (weighted frequency, 32,168,636) aged 19 and over who completed ophthalmologic and renal functional examinations were evaluated. Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate of < 60 ml/min/1.73 m² or proteinuria greater than 1+. Seven standard photographs from the Early Treatment for Diabetic Retinopathy Study were obtained from each eye after pharmacological pupil dilatation. Diabetic retinopathy (DR) was defined as the presence of 1 or more retinal microaneurysms or retinal blot hemorrhages with or without more severe lesions. Vision-threatening diabetic retinopathy (VTDR) was defined as the presence of a clinically significant macular edema (CSME) or proliferative diabetic retinopathy.

Results

CKD was significantly associated with DR and VTDR (odds ratio (OR), 95% confidence interval (CI); 2.49(1.43-4.35) and 3.74(1.56-8.95), respectively) in the diabetic population. After controlling for confounders, however, CKD was significantly associated only with DR [adjusted OR (aOR), 95% CI; 2.34(1.04-5.28)]. In the subgroup analysis for CKD, only proteinuria was significantly associated with DR and VTDR (aOR, 95% CI; 4.56(1.51-13.77) and 5.61(1.06-29.87), respectively) in this population.

Conclusions

Our results show that CKD appears to be associated with DR and VTDR in a Korean diabetic population. In particular, proteinuria, not decreased eGFR, is more significantly associated with DR or VTDR.     

The Associations between Serum Zinc Levels and Metabolic Syndrome in the Korean Population: Findings from the 2010 Korean National Health and Nutrition Examination Survey

The prevalence of metabolic syndrome has been increasing rapidly worldwide. The functions of zinc may have a potential association with metabolic syndrome, but such associations have not been investigated extensively. Therefore, we examined the relationship between serum zinc levels and metabolic syndrome or metabolic risk factors among South Korean adults ≥20 years of age. The analysis used data from the Korean National Health and Nutrition Examination Survey, a cross-sectional survey of Korean civilians, conducted from January to December 2010. A total of 1,926 participants were analyzed in this study. Serum zinc levels in men were negatively associated with elevated fasting glucose (adjusted odds ratio [aOR], 0.58; 95% confidence interval [CI], 0.36–0.93) and positively associated with elevated triglycerides (aOR, 1.47; 95% CI, 1.01–2.13). A difference in serum zinc levels was detected in women, depending on the number of metabolic syndrome components (p = 0.002). Furthermore, serum zinc levels showed a decreasing trend with increasing numbers of metabolic syndrome components in women with metabolic syndrome. These findings suggest that serum zinc levels might be associated with metabolic syndrome or metabolic risk factors. Further gender-specific studies are needed to evaluate the effect of dietary or supplemental zinc intake on metabolic syndrome.     

Association between Reproductive Factors and Age-Related Macular Degeneration in Postmenopausal Women: The Korea National Health and Nutrition Examination Survey 2010-2012

Purpose

To examine the association between female reproductive factors and age-related macular degeneration (AMD) in postmenopausal women.

Design

Nationwide population-based cross-sectional study.

Methods

A nationally representative dataset acquired from the 2010–2012 Korea National Health and Nutrition Examination Survey was analyzed. The dataset involved information for 4,377 postmenopausal women aged ≥50 years with a fundus photograph evaluable for AMD in either eye. All participants were interviewed using standardized questionnaires to determine reproductive factors including menstruation, pregnancy, parity, lactation, and hormonal use. The association between reproductive factors and each type of AMD was investigated.

Results

The mean age of the study participants was 63.1±0.2 years. Mean ages at menarche and menopause were 16.1±0.0 and 49.2±0.1 years, respectively. The overall prevalence rates of early and late AMD were 11.2% (95% confidence interval [CI], 10.1–12.5) and 0.8% (95% CI, 0.5–1.2), respectively. When adjusted for age, neither smoking nor alcohol use was associated with the presence of any AMD or late AMD. Multivariate logistic regression analysis revealed age (OR, 1.12 per 1 year), duration of lactation (OR, 0.91 per 6 months), and duration of use of oral contraceptive pills (OCP) (OR, 1.10 per 6 months) as associated factors for late AMD. The other variables did not yield a significant correlation with the risk of any AMD or late AMD.

Conclusion

After controlling for confounders, a longer duration of lactation appeared to protect against the development of late AMD. A longer duration of OCP use was associated with a higher risk of late AMD.     

Prevalence of and Factors Associated with Albuminuria in the Korean Adult Population: The 2011 Korea National Health and Nutrition Examination Survey

Background

Microalbuminuria is associated with increased risk of renal disease and cardiovascular diseases even in non-diabetic subjects. High incidence rates of microalbuminuria have been found in a number of population-based studies. However, the prevalence and risk factors associated with microalbuminuria in the general population in Korea are unclear.

Objectives

The present study was performed to estimate the prevalence of microalbuminuria and investigate the associated risk factors in the general adult population using the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-2) data from 2011.

Methods

A total of 5,202 participants (mean age, 45.6 years; men, 2,337; women, 2,865) were included in the analysis. Microalbuminuria was evaluated in participants of KNHANES V-2 based on the urine albumin–creatinine ratio. Estimated glomerular filtration rate was calculated using the Modification of Diet in Renal Disease study equation.

Results

The weighted prevalence of microalbuminuria was 5.2% (95% CI, 4.4–6.1) in the general population. The prevalence of albuminuria is increased with age. After adjustment for age and sex, the presence of albuminuria was associated with increased waist circumference, systolic and diastolic blood pressure, aspartate aminotransferase, triglyceride, fasting plasma glucose, and the presence of hypertension and diabetes. In logistic regression analyses, older age, female sex, diabetes, hypertension, and serum aspartate aminotransferase were independently associated with the presence of albuminuria.

Conclusion

The prevalence of microalbuminuria was found to be 5.2%, and conventional risk factors for cardiovascular diseases are closely related to the presence of microalbuminuria in Korea. Microalbuminuria may be a useful marker to identify individuals with increased risk of cardiovascular disease.     

Association of Hearing Loss and Tinnitus with Health-Related Quality of Life: The Korea National Health and Nutrition Examination Survey

Background

Hearing loss and tinnitus are global public health concerns. There have been some studies suggesting a relationship between hearing loss and tinnitus and impaired health-related quality of life (HRQoL), but there have been no large cross-sectional epidemiologic studies of a representative sample of the entire country population investigating this possible association.

Objective

The aim of this study was to investigate the relationship between hearing loss and tinnitus and HRQoL in South Korea using data from the Korea National Health and Nutrition Examination Surveys during 2010–2012.

Methods

Cross-sectional data of 11,266 adults who completed the Korea National Health and Nutrition Examination Surveys were analyzed. Subjects were divided into four groups as follows: normal hearing without tinnitus, normal hearing with tinnitus, hearing loss without tinnitus, and hearing loss with tinnitus.

Results

Among the population that was ≥19 years of age, the prevalence of unilateral hearing loss was 9.69% and that of tinnitus in the prior 12 months was 32.76%. The hearing loss with tinnitus group had the highest percentage of subjects who responded “some or extreme problems” in all five dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) of HRQoL. After adjustment for age, gender, body mass index, smoking status, alcohol intake, regular exercise, house income, education level, diabetes, hypertension, and stress level, the HRQoL odds ratios (OR) were 1.47 (95% confidence interval [CI], 1.07–2.02) for mobility, 1.59 (95% CI, 1.07–2.37) for usual activity, and 1.84 (95% CI, 1.25–2.70) for anxiety/depression in the hearing loss with tinnitus group, compared with the normal hearing without tinnitus group. The ORs for the normal hearing with tinnitus group compared with the hearing loss without tinnitus group was increased in all five dimensions of HRQoL after adjustment for confounders.

Conclusion

Hearing loss with tinnitus has a considerable impact on HRQoL in the Korean population. In our study, the hearing loss without tinnitus group showed better a HRQoL than the normal hearing with tinnitus group.     

Thyroid Hormones and Electrocardiographic Parameters: Findings from the Third National Health and Nutrition Examination Survey

Introduction

Altered thyroid status exerts a major effect on the heart. Individuals with hypo- or hyperthyroidism showed various changes in electrocardiograms. However, little is known about how variations in thyroid hormone levels within the normal range affect electrical activities of the heart in the general population.

Methods and Results

We conducted a cross-sectional analysis of 5,990 men and women from the Third National Health and Nutrition Examination Survey. Serum total T4 was measured by immunoassay and TSH was measured by chemiluminescent assay. We categorized T4 and TSH into 7 groups with cut-offs at the 5^th, 20^th, 40^th, 60^th, 80^th, and 95^th percentiles of the weighted population distribution. Electrocardiographic parameters were measured from the standard 12-lead electrocardiogram. We found a positive linear association between serum total T4 level and heart rate in men, and a U-shape association between T4 and PR interval in men and women. TSH level was positively associated with QRS interval in men, while a U-shape association between TSH and QRS was observed in women. No clear graded association between thyroid hormones and corrected QT or JT was found, except that men in the highest category of T4 levels appeared to have longer corrected QT and JT, and men in the lowest category of T4 appeared to have shorter corrected QT and JT.

Conclusions

Variation in thyroid hormone levels in the general population, even within the normal range, was associated with various ECG changes.     

The Association between Metabolic Syndrome or Chronic Kidney Disease and Hearing Thresholds in Koreans: The Korean National Health and Nutrition Examination Survey 2009-2012

Background

The aim of this study was to determine whether metabolic syndrome (MetS) or chronic kidney disease (CKD) is associated with hearing thresholds in the general Korean population.

Patients and Methods

A total of 16,554 participants were included in this study. MetS was defined using the National Cholesterol Education Program Adult Treatment Panel III guidelines, and CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m² or a dipstick proteinuria result of ≥1+. The hearing thresholds were measured at 0.5, 1, 2, 3, 4, and 6 kHz. Low-frequency (Freq) was defined as pure-tone averages at 0.5 and 1 kHz, while Mid-Freq and High-Freq were defined as the average thresholds at mid-frequency (2 and 3 kHz) and high frequency (4 and 6 kHz), respectively.

Results

In men, the hearing thresholds were 15.1 ± 14.5 dB, 22.2 ± 21.3 dB, and 37.3 ± 26.5 dB for Low-, Mid-, and High-Freq, respectively. In women, the hearing thresholds were 14.9 ± 15.3 dB, 16.6 ± 18.0 dB, and 26.1 ± 21.5 dB for Low-, Mid-, and High-Freq, respectively. The hearing thresholds for men were significantly higher than the hearing thresholds for women in all 3 threshold categories. Male and female subjects with MetS or CKD had higher hearing thresholds than the subjects that did not have these disorders. In the multivariate analysis, MetS was associated with increased hearing thresholds in women, and CKD was associated with increased hearing thresholds in men and women.

Conclusion

MetS is associated with hearing thresholds in women, and CKD is associated with hearing thresholds in men and women. Therefore, patients with MetS or CKD should be closely monitored for hearing impairment.     

The relationship between hand osteoarthritis and serum leptin concentration in participants of the Third National Health and Nutrition Examination Survey

Introduction

Leptin has been suspected to contribute to the development of osteoarthritis (OA). However, this hypothesis has not been tested in large-scale hand OA cohorts. Our study aimed to determine whether there is a cross-sectional relationship between serum leptin levels and hand OA in a population-based sample of US adults.

Method

We used the Third National Health and Nutrition Examination Survey (NHANES III), a national cross-sectional population-based survey, to study the relationship between hand OA and serum leptin concentration. We applied previously established classification criteria for hand OA. Patients with rheumatoid arthritis were excluded. Potential confounders included sex, body mass index, the presence of polyarticular OA, diabetes, and total cholesterol. We estimated unadjusted mean leptin concentration by hand OA status and by all confounders. We further developed a linear regression model to assess mean leptin levels, adjusted for appropriate confounders.

Results

Of 2,477 subjects in the NHANES III sample that had a hand examination and did not have rheumatoid arthritis, 1,056 (42.6%) had a leptin measurement and were included in the analysis. Subjects with and without leptin measurement had similar demographic characteristics. We did not find any significant differences in mean serum leptin levels in subjects with symptomatic hand OA (7.38 ng/ml in males (95% confidence interval (CI) = 5.31, 9.46) and 21.55 ng/ml in females (95% CI = 17.08, 26.02)), asymptomatic hand OA (6.69 ng/ml in males (95% CI = 5.19, 8.18) and 17.09 ng/ml in females (95% CI = 15.00, 19.18)), and no hand OA (8.22 ng/ml in males (95% CI = 7.47, 8.97) and 20.77 ng/ml in females (95% CI = 18.01, 23.53)) in the unadjusted analysis. In a multivariable linear regression model that included variables of hand OA status, age, race/ethnicity, and obesity status, we found no statistically significant association between serum leptin and hand OA status.

Conclusions

In this cross-sectional study of a large representative US cohort, we did not find any evidence to support the hypothesis that serum leptin is associated with hand OA.