What if we prevent obesity? Risk reduction in knee osteoarthritis estimated through a meta‐analysis of observational studies

Objective

To summarize the overall relative risk of knee osteoarthritis (OA) associated with body mass index, and to estimate the potential risk reduction due to the control of this risk factor.

Methods

Six electronic databases were searched up to July 2010. Relative risk was estimated using odds ratio (OR). A random‐effects model was used to pool the results. Risk reduction was estimated using population‐attributable risk percentage (PAR%), i.e., the proportion of knee OA that would have been avoided if obesity had not been present in the population. The percentage of obesity in different populations was obtained from the International Obesity Task Force.

Results

Forty‐seven studies (446,219 subjects) were included in the meta‐analysis, of which there were 14 cohort, 19 cross‐sectional, and 14 case–control studies. The overall pooled ORs for overweight and obese individuals were 2.02 (95% confidence interval [95% CI] 1.84–2.22) and 3.91 (95% CI 3.32–4.56), respectively. Risk reduction in terms of PAR% for knee OA varied from 8% in China to 50% in the US, depending on the prevalence of overweight and obesity. The reduction was greater in severe symptomatic OA than in asymptomatic radiographic OA.

Conclusion

Obesity is a risk factor for many conditions, including knee OA. The benefit of modifying this risk factor may cause significant risk reduction of knee OA in the general population, especially in Western countries where obesity is prevalent.     

Prevalence and correlates of arthritis‐attributable work limitation in the US population among persons ages 18–64: 2002 National Health Interview Survey Data

Objective

To estimate the national prevalence of arthritis‐attributable work limitation (AAWL) among persons ages 18–64 with doctor‐diagnosed arthritis and examine correlates of AAWL.

Methods

Using the 2002 National Health Interview Survey, we estimated the prevalence of AAWL (limited in whether individuals work, the type of work they do, or the amount of work they do) and correlates of AAWL in univariable and multivariable‐adjusted logistic regression analyses. Survey data were analyzed in SAS and SUDAAN to account for the complex sample design.

Results

A total of 5.3% of all US adults ages 18–64 reported AAWL; in this age group, AAWL is reported by ～30% of those who report arthritis. The prevalence of AAWL was highest among people ages 45–64 years (10.2%), women (6.3%), non‐Hispanic blacks (7.7%), people with less than a high school education (8.6%), and those with an annual household income <$20,000 (12.6%). AAWL was substantially increased among people with arthritis‐attributable activity limitations (multivariable‐adjusted odds ratio [OR] 9.1, 95% confidence interval [95% CI] 7.1–11.6). The multivariable‐adjusted likelihood of AAWL was moderately higher among non‐Hispanic blacks (OR 1.6, 95% CI 1.2–2.3), Hispanics (OR 1.8, 95% CI 1.2–2.6), and people with high levels of functional/social/leisure limitations (OR 1.8, 95% CI 1.4–2.3) and was decreased among those with a college education (OR 0.6, 95% CI 0.4–0.8).

Conclusion

AAWL is highly prevalent, affecting millions of Americans and one‐third of adults with doctor‐diagnosed arthritis. Findings suggest the need for more targeted research to better understand the natural history, success of interventions, and effects of policy on AAWL. Public health interventions, including self‐management education programs, may be effective in countering AAWL.     

Medical Expenditures and Earnings Losses Among US Adults With Arthritis in 2013

Objective

We estimated the economic impact of arthritis using 2013 US Medical Expenditure Panel Survey (MEPS) data.

Methods

We calculated arthritis‐attributable and all‐cause medical expenditures for adults age ≥18 years and arthritis‐attributable earnings losses among those ages 18–64 years who had ever worked. We calculated arthritis‐attributable costs using multistage regression‐based methods, and conducted sensitivity analyses to estimate costs for 2 other arthritis definitions in MEPS.

Results

In 2013, estimated total national arthritis‐attributable medical expenditures were $139.8 billion (range $135.9–$157.5 billion). Across expenditure categories, ambulatory care expenditures accounted for nearly half of arthritis‐attributable expenditures. All‐cause expenditures among adults with arthritis represented 50% of the $1.2 trillion national medical expenditures among all US adults in MEPS. Estimated total national arthritis‐attributable earning losses were $163.7 billion (range $163.7–$170.0 billion). The percentage with arthritis who worked in the past year was 7.2 percentage points lower than those without arthritis (76.8% [95% confidence interval (95% CI)] 75.0–78.6 and 84.0% [95% CI 82.5–85.5], respectively, adjusted for sociodemographics and chronic conditions). Total arthritis‐attributable medical expenditures and earnings losses were $303.5 billion (range $303.5–$326.9 billion).

Conclusion

Total national arthritis‐attributable medical care expenditures and earnings losses among adults with arthritis were $303.5 billion in 2013. High arthritis‐attributable medical expenditures might be reduced by greater efforts to reduce pain and improve function. The high earnings losses were largely attributable to the substantially lower prevalence of working among those with arthritis compared to those without, signaling the need for interventions that keep people with arthritis in the workforce.     

Body mass index,obesity, and prevalent gout in the United States in 1988–1994 and 2007–2010

Objective

To determine the association and prevalence of gout among overweight, obese, and morbidly obese segments of the US population.

Methods

Among participants (age ≥20 years) of the National Health and Nutrition Examination Surveys in 1988–1994 and 2007–2010, gout status was ascertained by self‐report of a physician diagnosis. Body mass index (BMI) was examined in categories of <18.5 kg/m², 18.5–24.9 kg/m², 25–29.9 kg/m², 30–34.9 kg/m², and ≥35 kg/m² and as a continuous variable. The cross‐sectional association of BMI category with gout status was adjusted for demographic and obesity‐related medical disorders.

Results

In the US, the crude prevalence of gout was 1–2% among participants with a normal BMI (18.5–24.9 kg/m²), 3% among overweight participants, 4–5% with class I obesity, and 5–7% with class II or class III obesity. The adjusted prevalence ratio comparing the highest to a normal BMI category was 2.46 (95% confidence interval [95% CI] 1.44–4.21) in 1988–1994 and 2.21 (95% CI 1.50–3.26) in 2007–2010. Notably, there was a progressively greater prevalence ratio of gout associated with successively higher categories of BMI. In both survey periods, for an average American adult standing 1.76 meters (5 feet 9 inches), a 1‐unit higher BMI, corresponding to 3.1 kg (～6.8 pounds) greater weight, was associated with a 5% greater prevalence of gout, even after adjusting for serum uric acid (P < 0.001).

Conclusion

Health care providers should be aware of the elevated burden of gout among both overweight and obese adults, applicable to both women and men, and observed among non‐Hispanic whites, non‐Hispanic African Americans, and Mexican Americans in the US.     

Physical inactivity in patients with rheumatoid arthritis: Data from twenty‐one countries in a cross‐sectional,international study

Objective

Regular physical activity is associated with decreased morbidity and mortality. Traditionally, patients with rheumatoid arthritis (RA) have been advised to limit physical exercise. We studied the prevalence of physical activity and associations with demographic and disease‐related variables in patients with RA from 21 countries.

Methods

The Questionnaires in Standard Monitoring of Patients with Rheumatoid Arthritis (QUEST‐RA) is a cross‐sectional study that includes a self‐report questionnaire and clinical assessment of nonselected consecutive outpatients with RA who are receiving usual clinical care. Frequency of physical exercise (≥30 minutes with at least some shortness of breath, sweating) is queried with 4 response options: ≥3 times weekly, 1–2 times weekly, 1–2 times monthly, and no exercise.

Results

Between January 2005 and April 2007, a total of 5,235 patients from 58 sites in 21 countries were enrolled in QUEST‐RA: 79% were women, >90% were white, mean age was 57 years, and mean disease duration was 11.6 years. Only 13.8% of all patients reported physical exercise ≥3 times weekly. The majority of the patients were physically inactive with no regular weekly exercise: >80% in 7 countries, 60–80% in 12 countries, and 45% and 29% in 2 countries, respectively. Physical inactivity was associated with female sex, older age, lower education, obesity, comorbidity, low functional capacity, and higher levels of disease activity, pain, and fatigue.

Conclusion

In many countries, a low proportion of patients with RA exercise. These data may alert rheumatologists to motivate their patients to increase physical activity levels.     

Are US adults with arthritis meeting public health recommendations for physical activity?

Objective

To estimate the prevalence of US adults with self‐reported, doctor‐diagnosed arthritis (without specifying the type of rheumatic disease) who are meeting the US Surgeon General's recommendations for physical activity.

Methods

Using population‐based survey data from the 2001 Behavioral Risk Factor Surveillance Survey, we classified respondents according to their arthritis status and their level of physical activity (i.e., physically inactive, insufficiently active, or meeting recommendations). Prevalence data were weighted to take account of the complex sampling design, and were broken down by a variety of demographic characteristics such as race, education, and body weight.

Results

Nearly one‐quarter (23%) of US adults reported having doctor‐diagnosed arthritis. Among adults with arthritis, 23.8% were physically inactive, 38% reported insufficient levels of physical activity, and 38.3% reported meeting the recommendations for physical activity. The highest prevalence of inactivity in adults with arthritis was found among those subjects with fewer than 8 years of formal education (47.6%), those with 9–11 years of education (35.5%), those who were African American (35.4%), those whose age was ≥65 years (31.1%), and those who were Hispanic (30.4%).

Conclusion

Despite the benefits of physical activity, more than 60% of adults with arthritis do not meet the physical activity recommendations. Efforts should be made to ensure that adults with arthritis are made aware of the benefits of physical activity, and that interventions are prescribed to assist these individuals in becoming more physically active.

     

The United States and Canada as a coupled epidemiological system: An example from hepatitis A

Background  

Hepatitis A (HA) is a low-incidence, non-endemic disease in Canada and the United States (US). However, a large difference in HA incidence between Canada and HA-endemic countries has made travel an important contributor to hepatitis A prevalence in Canada. There is also a (smaller) incidence differential between Canada and the US. Although the US has only moderately higher HA incidence, the volume of travel by Canadians to the US is many times higher than travel volume to endemic countries. Hence, travel to the US may constitute a source of low to moderate risk for Canadian travelers. To our knowledge, travel to the US has never been included as a potential risk factor for HA infection in Canadian epidemiologic analyses. The objective of this study was to use dynamic models to investigate the possible effects on hepatitis A incidence in Canada due to (1) implementing vaccination in the US, and (2) varying the volume of travel by Canadians to the US.     

Inactivity‐associated medical costs among US adults with arthritis

Objective

To analyze direct medical costs among US adults with arthritis and estimate the proportion associated with inactivity.

Methods

In the 1987 National Medical Expenditure Survey, arthritis was defined using questions on self‐reported, doctor‐diagnosed arthritis or rheumatism. Physical activity was defined using a self‐report question on level of activity. Inactivity‐associated medical costs were derived by subtracting costs for active adults from costs for inactive adults after controlling for functional limitation.

Results

Among 5,486 adults with arthritis, inactive persons had higher medical costs than did active persons in all demographic groups examined. In multivariate models adjusting for key covariates, the proportion of costs associated with inactivity averaged 12.4% ($1,250 in 2000 dollars) and ranged from 7.8% to 14.3% among various demographic groups.

Conclusion

Inactivity‐associated medical costs among persons with arthritis are considerable. Physical activity interventions may be a cost‐effective strategy for reducing the burden of arthritis.

     

Quantifying the impact of transient joint symptoms,chronic joint symptoms,and arthritis: A population‐based approach

Objective

To estimate the prevalence and co‐occurrence of self‐reported doctor‐diagnosed arthritis, chronic joint symptoms (pain, aching, stiffness, or swelling on most days for a month), and transient joint symptoms (pain, aching, stiffness, or swelling but not on most days for a month), and to compare the sociodemographic characteristics, activity limitations, and health‐related quality of life (HRQOL) of people with joint conditions with those who have no self‐reported doctor‐diagnosed arthritis and no joint symptoms.

Methods

Data from the 2004 population‐based South Australian Health Omnibus Survey (n = 2,840, ages 18–96 years) were used in the study. Activity limitations were assessed using 10 activity limitations questions from the Short Form 36 health survey. HRQOL was assessed using the Assessment of Quality of Life scale.

Results

Half of all respondents reported having joint problems, with 26%, 11%, and 13% reporting self‐reported doctor‐diagnosed arthritis, chronic joint symptoms, and transient joint symptoms, respectively. Chronic joint conditions (self‐reported doctor‐diagnosed arthritis and chronic joint symptoms) accounted for 74% of all joint problems and were associated with higher odds of activity limitations and poorer HRQOL. The frequency of transient and chronic joint symptoms was highest among middle‐aged participants (ages 45–54 years for transient and 45–64 years for chronic joint symptoms) and those who had a body mass index in the obese range. Prevalence of self‐reported doctor‐diagnosed arthritis increased with age and was higher among women and those who were overweight or obese.

Conclusion

This study documented the high prevalence and impact of joint conditions in the community. Chronic joint conditions affect daily life and are substantial barriers for effective public health interventions aimed at reducing obesity and inactivity.     

Different normalizations for body size and population attributable risk of left ventricular hypertrophy: the MAVI study

BACKGROUND: Different methods of normalizing left ventricular (LV) mass for body size identify generally similar relative risks of adverse cardiovascular outcome but with variable prevalences of LV hypertrophy (H). Preliminary results from a population with high prevalence of obesity suggest that the population attributable-risk percent (PAR%) of LVH is substantially higher when LV mass is normalized for allometric power of height. METHODS: We calculated the PAR% of LVH by different definitions in the cohort of the MAssa Ventricolare sinistra nell' Ipertensione (MAVI) study (n = 1019, 62% women), a population with low prevalence of obesity (22%, with only 3% and 0.1% in class II and class III obesity, respectively). Composite fatal and nonfatal cardiovascular events occurred in 53 participants (5.2%). RESULTS: Prevalence of LVH was between 28% and 56%, with slight greater values for height-based normalization. Age- and sex-adjusted hazard ratios were comprised between 1.37 and 1.44 for different measures of LV mass index. The PAR% was not meaningfully different among the different methods of normalization (between 47% and 56%), and height-based methods showed in general a performance similar to body surface area-based normalizations. CONCLUSIONS: In a large clinical population of hypertensive subjects with low prevalence of obesity, population risk attributable to LV hypertrophy was not meaningfully different in relation to the type of normalization of LV mass for body size. Height-based methods perform as well as body surface area-based ones. We suggest that the prevalence of obesity in hypertensive populations might substantially influence differences in population risk attributable to LVH identified by different methods of normalizing LV mass.     

Self-management strategies in overweight and obese Canadians with arthritis

Objective

To estimate the prevalence of overweight and obese Canadians with arthritis and to describe their use of arthritis self‐management strategies, as well as explore the factors associated with not engaging in any self‐management strategies.

Methods

Respondents to the 2009 Survey on Living with Chronic Diseases in Canada, a nationally representative sample of 4,565 Canadians age ≥20 years reporting health professional–diagnosed arthritis (including more than 100 rheumatic diseases and conditions), were asked about the impact of their arthritis and how it was managed. Among the overweight (body mass index [BMI] 25–29.9 kg/m²) and obese (BMI ≥30 kg/m²) individuals with arthritis (n = 2,869), the use of arthritis self‐management strategies (i.e., exercise, weight control/loss, classes, and community‐based programs) were analyzed. Log binomial regression analyses were used to examine factors associated with engaging in none versus any (≥1) of the 4 strategies.

Results

More than one‐quarter (27.4%) of Canadians with arthritis were obese and an additional 39.9% were overweight. The overweight and obese individuals with arthritis were mostly female (59.5%), age ≥45 years (89.7%), and reported postsecondary education (69.0%). While most reported engagement in at least 1 self‐management strategy (84.9%), less than half (45.6%) engaged in both weight control/loss and exercise. Factors independently associated with not engaging in any self‐management strategies included lower education, not taking medications for arthritis, and no clinical recommendations from a health professional.

Conclusion

Fewer than half of the overweight and obese Canadians with arthritis engaged in both weight control/loss and exercise. The provision of targeted clinical recommendations (particularly low in individuals that did not engage in any self‐management strategies) may help to facilitate participation.     

Impact of dietary and lifestyle factors on the prevalence of hypertension in Western populations

The impact of dietary and lifestyle factors on the prevalence of hypertension was quantified for Finland, Italy, The Netherlands, UK and USA. For this purpose, we combined data of blood pressure (BP) and risk factors distributions in these five countries with BP estimates from randomized controlled trials of dietary and lifestyle factors to obtain population attributable risk percentages (PAR%) for hypertension. Overweight made a substantial contribution to hypertension (PAR%: 11-17%), as was the case for excessive sodium intake (9-17%), low potassium intake (4-17%), physical inactivity (5-13%), and low intake of fish oil (3-16%). PAR% were smaller for low calcium intake (2-8%), low magnesium intake (4-8%), excessive coffee consumption (1-9%) and excessive alcohol intake (2-3%). We conclude that diet and lifestyle have a major impact on hypertension in Western societies. The relative significance of different risk factors varies among populations, which is important for preventive strategies.     

Chronic liver disease mortality attributable to hepatitis B and C in New Zealand

BACKGROUND: This research aimed to estimate the prevalence and population attributable risk percent (PAR%) of hepatitis B (HBV) and C (HCV) infection among chronic liver disease (CLD) deaths in New Zealand. The PAR% is the percentage of CLD cases attributable to either HBV or HCV. Within New Zealand, there are large differences in HBV prevalence by ethnic group, so prevalence and PAR% estimates were made separately for the three major ethnic groups. METHODS: The study sample was selected from CLD deaths between 1992 and 1997. Data were extracted from hospital records and coroners' reports. The prevalence and PAR% of HBV and HCV were estimated. RESULTS: Data were extracted for 303 of 359 decedents selected for inclusion. Hepatitis B virus and HCV test results were identified in 67 and 43%, respectively. Among those cases tested, the prevalence (and estimated PAR%) of HBV infection was 68% (PAR% 66%) for Pacific people, 54% (PAR% 52%) for Maori and 10% (PAR% 10%) for European New Zealanders. The prevalence (and estimated PAR%) of past or present HCV infection ranged between 8 and 15% (PAR% 8-14%) for the three major ethnic groups. CONCLUSIONS: The present study has demonstrated that HBV and HCV infections are important contributors to CLD mortality in New Zealand. With the introduction of universal hepatitis B vaccination in the late 1980s, we would expect the burden of CLD deaths attributable to HBV to decrease in the future. However, the burden of CLD deaths due to HCV is likely to increase.     

Arthritis restricts volunteer participation: Prevalence and correlates of volunteer status among adults with arthritis

Objective

To estimate, among adults ages ≥45 years with arthritis, the prevalence and correlates of 1) volunteering, 2) arthritis‐attributable restrictions among volunteers, and 3) arthritis as the main barrier to volunteering (AMBV) among non‐volunteers.

Methods

Data were from the 2005–2006 Arthritis Conditions Health Effects Survey, a cross‐sectional random‐digit–dialed national telephone survey of noninstitutionalized US adults ages ≥45 years with self‐reported, doctor‐diagnosed arthritis. Respondents (n = 1,793; weighted population 37.7 million) were asked if they currently volunteer (work outside the home without pay). Volunteers were asked if arthritis affects their amount or type of volunteering (arthritis‐attributable volunteer limitation [AAVL]). Non‐volunteers were asked if arthritis is the main reason they do not volunteer (AMBV). Univariable and multivariable‐adjusted logistic regression analyses were performed to estimate associations between potential correlates and each outcome.

Results

One‐third of the respondents reported volunteering. Among volunteers, 41% (4.9 million) reported AAVL. Among non‐volunteers, 27% (6.8 million) reported AMBV. Fair/poor self‐rated health was significantly associated with less volunteering (multivariable‐adjusted odds ratio [OR] 0.5, 95% confidence interval [95% CI] 0.4–0.8) and greater AAVL (multivariable‐adjusted OR 2.1, 95% CI 1.1–4.0) and AMBV (multivariable‐adjusted OR 1.8, 95% CI 1.2–2.7). Poor physical function was the most strongly associated correlate of both AAVL and AMBV (multivariable‐adjusted ORs 8.0 and 4.3, respectively).

Conclusion

Volunteering is an important role with individual and societal benefits, but almost 12 million adults with arthritis are limited or do not participate in volunteering due to arthritis. Individuals with restrictions in volunteering reported a substantial burden of poor physical function and may benefit from effective, underused interventions designed to improve physical function, delay disability, and enhance arthritis self‐management.     

Medical cost of type 2 diabetes attributable to physical inactivity in the United States in 2012

Aims

Type 2 diabetes has grown to epidemic proportions in the U.S. and physical activity levels in the population continues to remain low, although it is one of the primary preventive strategies for diabetes. The objectives of this study were to estimate the direct medical costs of type 2 diabetes attributable to not meeting physical activity Guidelines and to physical inactivity in the U.S. in 2012.

Characterizing adults with Type 2 diabetes mellitus and intellectual disability: outcomes of a case‐finding study

Aims

To report the results of a case‐finding study conducted during a feasibility trial of a supported self‐management intervention for adults with mild to moderate intellectual disability and Type 2 diabetes mellitus, and to characterize the study sample in terms of diabetes control, health, and access to diabetes management services and support.

Methods

We conducted a cross‐sectional case‐finding study in the UK (March 2013 to June 2015), which recruited participants mainly through primary care settings. Data were obtained from medical records and during home visits.

Results

Of the 325 referrals, 147 eligible individuals participated. The participants’ mean (sd ) HbA_1c concentration was 55 (15) mmol/mol [7.1 (1.4)%] and the mean (sd ) BMI was 32.9 (7.9) kg/m², with 20% of participants having a BMI >40 kg/m². Self‐reported frequency of physical activity was low and 79% of participants reported comorbidity, for example, cardiovascular disease, in addition to Type 2 diabetes. The majority of participants (88%) had a formal or informal supporter involved in their diabetes care, but level and consistency of support varied greatly. Post hoc exploratory analyses showed a significant association between BMI and self‐reported mood, satisfaction with diet and weight.

Conclusions

We found high obesity and low physical activity levels in people with intellectual disability and Type 2 diabetes. Glycaemic control was no worse than in the general Type 2 diabetes population. Increased risk of morbidity in this population is less likely to be attributable to poor glycaemic control and is probably related, at least in part, to greater prevalence of obesity and inactivity. More research, focused on weight management and increasing activity in this population, is warranted.     

Associations of multiple unhealthy lifestyle behaviors with overweight/obesity and abdominal obesity among Brazilian adolescents: A country-wide survey

Background and Aims

Physical inactivity, unhealthy diet, smoking and heavy drinking are four key unhealthy lifestyle behaviors (ULB) that may influence body weight and obesity development. More recently, sedentary time has been recognized as another potentially emerging ULB related to obesity. We therefore investigated the association of multiple ULB with overweight/obesity and abdominal obesity among Brazilian adolescents.