The relationship between body mass index and hip osteoarthritis: a systematic review and meta-analysis

Occupational mechanical exposures as risk factor for shoulder osteoarthritis: a systematic review

OBJECTIVES

The aim of this systematic review was to study the association between occupational mechanical exposures and shoulder osteoarthritis (OA).

METHODS

A protocol was registered in PROSPERO. Four databases were systematically searched based on PECOS criteria. Outcome was defined as shoulder OA (acromioclavicular (AC) and/or glenohumeral OA) and exposure as occupational mechanical exposures (vibration, upper arm elevation, force, lifting, repetition, and combined mechanical exposures). We included epidemiological studies estimating the prevalence of shoulder OA or the association between occupational mechanical exposures and shoulder OA. Two researchers independently screened articles, performed data extraction, and assessed the risk of bias and level of evidence using GRADE.

RESULTS

A total of 1642 articles were screened, of which 7 met the inclusion criteria. Four studies were assessed as having a high risk of bias, 1 with a moderate risk, and 2 with a low risk. Based on job titles, higher prevalence estimates (2.9% to 61.8%) were found in exposed job groups. For all occupational mechanical exposures, exposure-response relations were found in relation to AC OA. For vibration, the odds ratio (OR) ranged between 1.7 and 3.1 in the highest exposure groups, while the ORs for upper arm-elevation, force, lifting, repetition, and combined mechanical exposures ranged between 0.5 to 2.2, 1.3 to 1.8, 7.3 to 10.3, 2.4, and 2.2 to 2.9. Low or very low level of evidence was found for all exposures.

CONCLUSIONS

This systematic review found an indication of an association between occupational mechanical exposures and shoulder OA, especially AC OA. However, the level of evidence varied between low and very low. High-quality studies assessing the association and differentiating between the specific shoulder joints are highly warranted.

Triiodothyronine (T3) promotes browning of white adipose through inhibition of the PI3K/AKT signalling pathway

Obesity arises from an imbalance between energy consumption and energy expenditure, and thyroid hormone levels serve as a determinant of energy expenditure. We conducted experiments at the animal and cellular levels and combined those findings with clinical data to elucidate the role of triiodothyronine (T3) in facilitating the browning of white adipose tissue (WAT) and its underlying mechanism. The results showed (i) the impaired metabolic function of local WAT and the compensatory elevation of systemic thermogenesis in obesity; (ii) T3 treatment of white adipocytes in vitro and local WAT in vivo induced a shift towards a morphologically "brown" phenotype, accompanied by upregulation of mRNA and protein expression of browning-related and mitochondrial function markers, which suggest that T3 intervention promotes the browning of WAT; and (iii) the aforementioned processes could be modulated through inhibition of the PI3K/AKT signalling pathway; however, whether T3 affects the PI3K/AKT signalling pathway by affecting insulin signalling remains to be studied and clarified. The results of our study indicate that T3 treatment promotes browning of WAT through inhibition of the PI3K/AKT signalling pathway; these findings offer novel perspectives regarding the potential of localised therapies for addressing WAT volume in individuals with obesity.

Social Risk Profile and Cardiovascular-Kidney-Metabolic Syndrome in US Adults

BACKGROUND

Poor cardiovascular-kidney-metabolic (CKM) health is associated with premature mortality and excess morbidity in the United States. Adverse social conditions have a prominent impact on cardiometabolic diseases during the life course. We aim to examine the association between social risk profile (SRP) and CKM multimorbidity among US adults.

METHODS AND RESULTS

We used data from the National Health and Nutrition Examination Survey from 1999 to 2018. The definition of CKM syndrome is the coexistence of subclinical or clinical cardiovascular disease, chronic kidney disease, and metabolic disorders. We classified participants by 4 CKM stages according to the different clinical severity of different forms of CKM syndrome. We calculated the summed number of positive SRP measures, including employed, high-income level, food secure, high education attainment, private insurance, owning a house, and married, as SRP scores and classified them into 4 levels by quartiles: low (0-2), lower-middle (3-4), upper-middle (5-6), and high (7-8). A total of 18 373 US adults, aged 20 to 79 years, were included in our analyses. There were 2567 (9.4%) participants with low SRP score level. Most individual SRP measures and a combined SRP score were associated with CKM stages. Compared with high SRP score level, low SRP level was associated with higher odds of having CKM stage 1 (odds ratio [OR], 1.34 [95% CI, 1.06-1.70]), CKM stage 2 (OR, 2.03 [95% CI, 1.59-2.58]), CKM stage 3 (OR, 5.28 [95% CI, 3.29-8.47]), and CKM stage 4 (OR, 5.97 [95% CI, 4.20-8.49]).

CONCLUSIONS

Cumulative social disadvantage, denoted by higher SRP burden, was associated with higher odds of CKM multimorbidity, independent of demographic and lifestyle factors.

Genetic determinants of obesity in Korean populations: exploring genome-wide associations and polygenic risk scores

East Asian populations exhibit a genetic predisposition to obesity, yet comprehensive research on these traits is limited. We conducted a genome-wide association study (GWAS) with 93,673 Korean subjects to uncover novel genetic loci linked to obesity, examining metrics such as body mass index, waist circumference, body fat ratio, and abdominal fat ratio. Participants were categorized into non-obese, metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO) groups. Using advanced computational methods, we developed a multifaceted polygenic risk scores (PRS) model to predict obesity. Our GWAS identified significant genetic effects with distinct sizes and directions within the MHO and MUO groups compared with the non-obese group. Gene-based and gene-set analyses, along with cluster analysis, revealed heterogeneous patterns of significant genes on chromosomes 3 (MUO group) and 11 (MHO group). In analyses targeting genetic predisposition differences based on metabolic health, odds ratios of high PRS compared with medium PRS showed significant differences between non-obese and MUO, and non-obese and MHO. Similar patterns were seen for low PRS compared with medium PRS. These findings were supported by the estimated genetic correlation (0.89 from bivariate GREML). Regional analyses highlighted significant local genetic correlations on chromosome 11, while single variant approaches suggested widespread pleiotropic effects, especially on chromosome 11. In conclusion, our study identifies specific genetic loci and risks associated with obesity in the Korean population, emphasizing the heterogeneous genetic factors contributing to MHO and MUO.

Burden evaluation and prediction of osteoarthritis and site-specific osteoarthritis coupled with attributable risk factors in China from 1990 to 2030

OBJECTIVE

This study aimed to estimate and predict the burden of osteoarthritis (OA) and site-specific OA (hip, knee, hand, and others) from 1990 to 2030 and their attributable risk factors in China.

METHOD

Data were obtained from the Global Burden of Diseases 2019. The burden was estimated by analyzing the trends of prevalence, incidence, and disability-adjusted life years (DALY). Population attributable risk (PAR) was calculated to assess the impact of high body mass index (BMI). The prediction from 2020 to 2030 was implemented by Bayesian age-period-cohort analysis.

RESULTS

In China, prevalent cases, DALY, and incident cases of OA increased to 132.81 million, 4.72 million, and 10.68 million, respectively. Age-standardized rates (ASRs) of prevalence, DALYs, and incidence increased for OA and site-specific OA, especially for hip OA. Site-specific OA showed different susceptible peaking ages, and the burden for those over 50 years old became serious. Female preference existed in the trends for knee OA but not in those for hip, hand, and other OA. PARs of high BMI continued to increase, impacting knee OA more than hip OA and showing female preference. In the next decade, incident cases for OA and site-specific OA will continue to increase, despite that the ASR of OA incidence will decrease.

CONCLUSIONS

OA and site-specific OA remain huge public health challenges in China. The burden of OA and site-specific OA is increasing, especially among people over 50 years old. Health education, exercise, and removing modifiable risk factors contribute to alleviate the growing burden. Key Points • In China, the burden of osteoarthritis and site-specific osteoarthritis (hip, knee, hand, and others) as well as the Risk Factor (high body mass index) increased greatly from 1990 to 2019. • It is estimated that incident cases for OA and site-specific OA will continue to increase, despite that the ASR of OA incidence will decrease.

Glucagon-Like Peptide Receptor-1 Agonists Used for Medically-Supervised Weight Loss in Patients With Hip and Knee Osteoarthritis: Critical Considerations for the Arthroplasty Surgeon

Patients with morbid obesity and concomitant hip or knee osteoarthritis represent a challenging patient demographic to treat as these patients often present earlier in life, have more severe symptoms, and have worse surgical outcomes following total hip and total knee arthroplasty. Previously, bariatric and metabolic surgeries represented one of the few weight loss interventions that morbidly obese patients could undergo prior to total joint arthroplasty. However, data regarding the reduction in complications with preoperative bariatric surgery remain mixed. Glucagon-like peptide receptor-1 (GLP-1) agonists have emerged as an effective treatment option for obesity in patients with and without diabetes mellitus. Furthermore, recent data suggest these medications may serve as potential anti-inflammatory and disease-modifying agents for numerous chronic conditions, including osteoarthritis. This review will discuss the GLP-1 agonists and GLP-1/glucose-dependent insulinotropic polypeptide dual agonists currently available, along with GLP-1/glucose-dependent insulinotropic polypeptide/glucagon triple agonists presently being developed to address the obesity epidemic. Furthermore, this review will address the potential problem of GLP-1-related delayed gastric emptying and its impact on the timing of elective total joint arthroplasty. The review aims to provide arthroplasty surgeons with a primer for implementing this class of medication in their current and future practice, including perioperative instructions and perioperative safety considerations when treating patients taking these medications.

A New Clinical Examination Algorithm to Prescribe Conservative Treatment in People with Hip-Related Pain

Hip-related pain is a common issue in active adults affecting their quality of life, mobility, and overall function, and it can lead to persistent disability. However, diagnosing hip-related pain is challenging due to the many potential sources and causes, including intra-articular and extra-articular pathology, and referred pain from other areas (lumbar or groin related pain). To address this, there is a need for a clinical algorithm based on the best available evidence and expert consensus. This algorithm could guide healthcare professionals in assessing and managing patients with hip-related pain, during the diagnosis, test selection, intervention, monitoring, and promoting collaboration among various healthcare providers. This clinical algorithm for hip-related pain is a comprehensive, flexible, adaptable to different settings, and regularly updated to incorporate new research findings. This literature review aims to establish a clinical algorithm specifically for prescribing exercise treatment to patients with hip-related pain, addressing their individual needs and enhancing their overall care.

The associations of "weekend warrior" and regularly active physical activity with abdominal and general adiposity in US adults

OBJECTIVE

This study examined the association between physical activity patterns and abdominal and general adiposity.

METHODS

Data were extracted among 20- to 59-year-old participants in the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018. Abdominal and general adiposity was assessed by dual-energy x-ray absorptiometry (DXA) and anthropometric measures. DXA-measured indicators were further normalized into z scores. Physical activity levels were collected by questionnaire and classified as inactive, "weekend warrior" (WW), and regularly active (RA). Survey linear regression models were used to assess associations between physical activity patterns and adiposity indicators.

RESULTS

Among 9629 participants, 772 (8.2%) reported the WW pattern and 3277 (36.9%) reported the RA pattern. Compared with inactive, both WW and RA had lower DXA-measured abdominal adiposity (WW: β: -0.24, 95% CI: -0.38 to -0.10; RA: -0.18, 95% CI: -0.29 to -0.07), waist circumference (WW: β: -1.94, 95% CI: -3.16 to -0.73; RA: -1.31, 95% CI: -2.32 to -0.29), whole-body fat mass (WW: β: -0.16, 95% CI: -0.25 to -0.08; RA: -0.11, 95% CI: -0.18 to -0.04), and BMI (WW: β: -0.78, 95% CI: -1.27 to -0.28; RA: -0.47, 95% CI: -0.89 to -0.04).

CONCLUSIONS

The WW pattern was associated with similarly lower abdominal and general adiposity to the RA pattern versus the inactive pattern.

The Economic Impact of Obesity in Turkey: A Micro-Costing Analysis

Background

Turkey currently has the highest obesity prevalence among its European counterparts. 32% and 61% of the population live with obesity and overweight, respectively. Overweight and obesity are linked to non-communicable diseases that incur incremental health and economic costs. The significant public health concern warrants an assessment of the cost of obesity.

Methods

A micro-costing approach from the public payer perspective was conducted to estimate direct healthcare costs associated with ten obesity-related comorbidities (ORCs) in Turkey. Clinical practice guidelines and a systematic literature review informed ORCs and the respective cost categories. This was subsequently validated by a steering committee comprising seven experts. Seventy public sector physicians were surveyed to estimate healthcare resource use. Unit costs were derived from Social Security Institute's Healthcare Implementation Communique. Cost items were summed to determine the annual cost per patient per ORC, which was validated by the steering committee. Medical inflation was considered in a scenario analysis that varied resource unit costs.

Results

Chronic kidney disease, heart failure and type 2 diabetes are the costliest ORCs, incurring an annual cost of 28,600 TRY, 16,639 TRY and 11,993 TRY, respectively. Individuals in Turkey with any ORC triggered direct healthcare costs ranging 1857-28,600 TRY annually. Costs were driven by tertiary care resources arising from treatment-related adverse events, disease complications and inpatient procedures. In the scenario analysis, medical resource unit costs were inflated by 18.7% and 39.4%, triggering an average increase in cost across all ORCs of 1998 TRY and 4210 TRY, respectively.

Conclusion

Our findings confirm that obesity and its complications result in significant financial burden to the public healthcare system. By quantifying the burden of obesity across a comprehensive spectrum of ORCs, our study aims to support the economic case for investing in appropriate obesity interventions.

Association of High Body Mass Index With Postoperative Complications After Chest Masculinization Surgery

PURPOSE

Body mass index (BMI) requirements for transgender and nonbinary patients undergoing chest masculinization surgery (CMS) are not standardized and based on small sample sizes. This is the largest and first national retrospective study to determine the association between BMI and postoperative complications.

METHODS

The National Surgical Quality Improvement Program 2012-2020 was queried for CMS patients. The primary outcome was incidence of at least one complication within 30 days. Secondary outcomes were incidence of major and minor complications. Body mass index (in kilograms per square meter) was categorized as category 0 (<30), 1 (30-34.9), 2 (35-39.9), 3 (40-44.9), 4 (45-49.9), and 5 (≥50). Logistic regression was used to evaluate the association between BMI and outcomes.

RESULTS

Of 2317 patients, median BMI was 27.4 kg/m 2 (interquartile range, 23.4-32.2 kg/m 2 ). Body mass index range was 15.6 to 64.9 kg/m 2 . While increasing BMI was significantly associated with greater odds of at least one complication, no patients experienced severe morbidity, regardless of BMI. Patients with BMI ≥50 kg/m 2 had an adjusted odds ratio [aOR, 95% confidence interval (CI)] of 3.63 (1.02-12.85) and 36.62 (2.96->100) greater odds of at least one complication and urinary tract infection compared with nonobese patients, respectively. Patients with BMI ≥35 kg/m 2 had an adjusted odds ratio (95% CI) of 5.06 (1.5-17.04) and 5.13 (1.89-13.95) greater odds of readmission and surgical site infection compared with nonobese patients, respectively.

CONCLUSIONS

Chest masculinization surgery in higher BMI patients is associated with greater odds of unplanned readmission. Given the low risk for severe complications in higher BMI individuals, we recommend re-evaluation of BMI cutoffs for CMS patients.

Cancers attributable to overweight and obesity in Italy

BACKGROUND & AIMS

Overweight and obesity are associated with multiple cancers. We quantified the burden of cancer attributable to overweight and obesity in Italy.

METHODS

We estimated sex- and cancer site-specific population attributable fractions (PAFs) combining relative risks (from recent meta-analyses) with national obesity prevalence data (from a large sample survey conducted in 2005, to account for a 15-year lag period). Using nationwide mortality statistics and cancer registries data, we estimated the number of cancer cases and deaths attributable to overweight and obesity in Italy in 2020, based on the counterfactual scenario of a body mass index < 25 kg/m2.

RESULTS

3.6% of cancers in men and 4.0% in women in Italy were attributable to overweight and obesity, corresponding, respectively, to over 6900 and 7200 diagnoses in 2020. Attributable deaths were over 3600 in men and 2700 in women. PAFs (attributable cases) of overweight and obesity in men and women were, respectively, 38.1% (215 cases) and 21.8% (49 cases) for esophageal adenocarcinoma, 19.1% (1715 cases) and 14.5% (585 cases) for liver, 18.7% (1692 cases) and 16.7% (747 cases) for kidney, 13.7% (938 cases) and 10.1% (749 cases) for pancreatic, and 10.2% (2389 cases) and 3.4% (690 cases) for colorectal cancers. In women, PAFs were 22.3% (1859 cases) for endometrial and 5.7% (2556 cases) for post-menopausal breast cancer.

CONCLUSIONS

The cancer burden associated with overweight and obesity in Italy is considerable, but smaller compared to other high income countries, likely because of the lower prevalence of overweight and obesity in the Italian population.

Osteoarthritis and risk of type 2 diabetes: A two-sample Mendelian randomization analysis

BACKGROUND

Physical inactivity is an independent risk factor for type 2 diabetes (T2D). Osteoarthritis (OA) is a common joint disease that limits patients' physical activity, which may increase risk of other chronic diseases including T2D. However, studies evaluating the effect of OA on T2D are scarce. This study aimed to investigate the causal effect of knee and hip OA on risk of T2D from a genetic perspective.

METHODS

We performed two-sample Mendelian randomization (MR) analyses to obtain nonconfounding estimates of the effect of OA on T2D risk. Single nucleotide polymorphisms (SNPs) from genome-wide association studies were selected as genetic instruments for radiographic knee and hip OA (ie, Kellgren-Lawrence grade ≥2). The associations of these SNPs with T2D were evaluated in participants from the UK Biobank. Sensitivity analyses were conducted to test the robustness of the MR results.

RESULTS

Genetic predisposition of knee but not hip OA was significantly associated with an increased risk of T2D (knee OA: odds ratio [OR] 1.18, 95% confidence interval (CI) 1.09-1.27, p <.001; hip OA: OR 1.04, 95% CI 0.94-1.16, p = .425). Sensitivity analyses showed that the main findings are robust.

CONCLUSION

The current study provides genetic evidence supporting that knee OA is a potential risk factor for T2D.

Free Hip Arthroplasty Templating Software - Does it Work?

Background

Preoperative planning is important for successful total hip arthroplasty (THA) and has been historically performed using acetate templates. Digital software templating has been adopted for evaluating implant size, position, and alignment. Commercial software can be expensive, but free programs exist. Detroit Bone Setter (detroitbonesetter.com, Detroit, MI) is a freely available templating program, but hasn't been validated. Our study reports this program's accuracy for templating THA.

Methods

Sixty-five patients undergoing THA between 2017 and 2022 at 2 hospitals were included. All cases were templated by the senior author or orthopaedic trauma fellow prospectively or retrospectively in a blinded fashion. Direct anterior or posterior approaches were used based on attending surgeon's preference. A student's t-test was used to compare means of templated vs actual implant sizes of femoral and acetabular components.

Results

There was no significant difference between implanted (mean [M] = 6.4, standard deviation [SD] = 2.0) and templated femoral component sizes (M = 5.7, SD = 2.1). There was a significant difference between implanted (M = 57.0, SD = 3.9) and templated acetabular component sizes (M = 53.4, SD = 3.0). Bland-Altman testing demonstrated femoral components with positive measurement bias of 0.62, indicating slight overestimation of implant size. Acetabular component size was overestimated with positive measurement bias of 3.6 mm.

Conclusions

Detroit Bone Setter is advantageous as it is freely available and supports most major company implants. It accurately templated femoral component size but consistently overestimated acetabular component size by 3.6 mm. Further studies are needed prior to recommending its routine use for templating THA when other validated methods exist. It could be used with caution when no other methods are available.

Rural-urban differentials in child body mass index over time

BACKGROUND

The body mass index is a simple index based on weight and height that can be used to screen children and adults for potential weight problems. The objective of this study was to investigate urban-rural variations in child BMI and its distribution from 2006 to 2016 in four low and middle-income countries.

METHODS

This study used data from the Young Lives prospective cohort study conducted in Ethiopia, India, Peru, and Vietnam to assess the BMI change for children aged 5 to 15 between 2006 and 2016. We adopted a mixed-effect model to analyze the data.

RESULTS

The study revealed substantial changes and rises in BMI in Vietnam, Peru, India, and Ethiopia between 2006 and 2016. Peru had the highest BMI changes in both urban-rural areas. A low BMI was observed in Ethiopia and India. Urban-rural differences had a significant role in determining BMI variation. In urban Ethiopia, the mean BMI increased from 14.56 kg/m2 to 17.52 kg/m2, and in rural areas, it increased from 14.57 kg/m2 to 16.67 kg/m2. Similarly, in urban Vietnam, the BMI increased from 16 kg/m2 to 20.3 kg/m2, and in rural areas, it increased from 14.69 kg/m2 to 18.93 kg/m2.

CONCLUSIONS

The findings showed an increase in BMI changes in Ethiopia, India, Peru, and Vietnam from 2006 to 2016. Urban-rural differences have a significant contribution to determining BMI variation.

Change in medial frontal cerebral metabolite concentrations following bariatric surgery

Obesity is associated with adverse effects on brain health, including an increased risk of neurodegenerative diseases. Changes in cerebral metabolism may underlie or precede structural and functional brain changes. While bariatric surgery is known to be effective in inducing weight loss and improving obesity-related medical comorbidities, few studies have examined whether it may be able to improve brain metabolism. In the present study, we examined changes in cerebral metabolite concentrations in participants with obesity who underwent bariatric surgery. Thirty-five patients with obesity (body mass index ≥ 35 kg/m2 ) were recruited from a bariatric surgery candidate nutrition class. They completed single voxel proton magnetic resonance spectroscopy at baseline (presurgery) and within 1 year postsurgery. Spectra were obtained from a large medial frontal brain region using a PRESS sequence on a 3-T Siemens Verio scanner. The acquisition parameters were TR = 3000 ms and TE = 37 ms. Tissue-corrected metabolite concentrations were determined using Osprey. Paired t-tests were used to examine within-subject change in metabolite concentrations, and correlations were used to relate these changes to other health-related outcomes, including weight loss and glycated hemoglobin (HbA1c ), a measure of blood sugar levels. Bariatric surgery was associated with a reduction in cerebral choline-containing compounds (Cho; t [34] = - 3.79, p < 0.001, d = -0.64) and myo-inositol (mI; t [34] = - 2.81, p < 0.01, d = -0.47) concentrations. There were no significant changes in N-acetyl-aspartate, creatine, or glutamate and glutamine concentrations. Reductions in Cho were associated with greater weight loss (r = 0.40, p < 0.05), and reductions in mI were associated with greater reductions in HbA1c (r = 0.44, p < 0.05). In conclusion, participants who underwent bariatric surgery exhibited reductions in cerebral Cho and mI concentrations, which were associated with improvements in weight loss and glycemic control. Given that elevated levels of Cho and mI have been implicated in neuroinflammation, reduction in these metabolites after bariatric surgery may reflect amelioration of obesity-related neuroinflammatory processes. As such, our results provide evidence that bariatric surgery may improve brain health and metabolism in individuals with obesity.

Obesity is associated with an increased risk of undergoing hip replacement in Australia

BACKGROUND

Obesity is a known risk factor for the development of hip osteoarthritis. The aim of this study was to investigate whether obesity is associated with the risk of undergoing total hip replacement (THR) in Australia.

METHODS

A cohort study was conducted comparing data from the Australian Bureau of Statistics and the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from 2017 to 2018. Body mass index (BMI) data for patients undergoing primary total hip replacement and resurfacing for osteoarthritis were obtained from the AOANJRR. The distribution of THR patients by BMI category was compared to the general population, in age and sex sub-groups.

RESULTS

During the study period, 32 495 primary THR were performed for osteoarthritis in Australia. Compared to the general population, there was a higher prevalence of Class I, II and III obesity in patients undergoing THR in both sexes aged 35-74 years. Class III obese females and males aged 55-64 years were 2.9 and 1.7 times more likely to undergo THR, respectively (P < 0.001). Class III obese females and males underwent THR on average 5.7 and 7.0 years younger than their normal weight counterparts, respectively.

CONCLUSION

Obese Australians are at increased risk of undergoing THR, and at a younger age.

Potential of omega-3 and conjugated fatty acids to control microglia inflammatory imbalance elicited by obesogenic nutrients

High-fat diet-induced obesity detrimentally affects brain function by inducing chronic low-grade inflammation. This neuroinflammation is, at least in part, likely to be mediated by microglia, which are the main immune cell population in the brain. Microglia express a wide range of lipid-sensitive receptors and their activity can be modulated by fatty acids that cross the blood-brain barrier. Here, by combining live cell imaging and FRET technology we assessed how different fatty acids modulate microglia activity. We demonstrate that the combined action of fructose and palmitic acid induce Ikβα degradation and nuclear translocation of the p65 subunit nuclear factor kB (NF-κB) in HCM3 human microglia. Such obesogenic nutrients also lead to reactive oxygen species production and LynSrc activation (critical regulators of microglia inflammation). Importantly, short-time exposure to omega-3 (EPA and DHA), CLA and CLNA are sufficient to abolish NF-κB pathway activation, suggesting a potential neuroprotective role. Omega-3 and CLA also show an antioxidant potential by inhibiting reactive oxygen species production, and the activation of LynSrc in microglia. Furthermore, using chemical agonists (TUG-891) and antagonists (AH7614) of GPR120/FFA4, we demonstrated that omega-3, CLA and CLNA inhibition of the NF-κB pathway is mediated by this receptor, while omega-3 and CLA antioxidant potential occurs through different signaling mechanisms.

Local Patterns in 2-Year T1ρ and T2 Changes of Hip Cartilage Are Related to Sex and Functional Data: A Prospective Evaluation on Hip Osteoarthritis Participants

BACKGROUND

Although T1ρ and T2 have emerged as early indicators for hip osteoarthritis (OA), there is little information regarding longitudinal changes across the cartilage in the early stages of this disease.

PURPOSE

To characterize the variability in 2-year hip cartilage T1ρ and T2 changes and investigate associations between these patterns of change and common indicators of hip OA.

STUDY TYPE

Prospective.

POPULATION

A total of 25 women (age: 51.9 ± 16.3 years old; BMI: 22.6 ± 2.0 kg/m2 ) and 17 men (age: 55.8 ± 14.9 years old; body mass index (BMI): 24.4 ± 3.8 kg/m2 ) who were healthy or with early-to-moderate hip OA.

FIELD STRENGTH/SEQUENCE

A 3 T MRI (GE), 3D combined T1ρ /T2 magnetization-prepared angle-modulated partitioned k-space spoiled gradient echo snapshots.

ASSESSMENT

Principal component (PC) analysis of Z-score difference maps of 2-year changes in hip cartilage T1ρ and T2 relaxation times, participant hip disability and osteoarthritis outcome scores (HOOS) and functional tests at 2-year follow-up.

STATISTICAL TESTS

Shapiro-Wilk test, unpaired t-tests, Kruskal Wallis tests, Pearson or Spearman (ρ) correlations. Significance was set at P < 0.05.

RESULTS

Women (-6.40 ± 14.48) had significantly lower T1ρ PC1 scores than men (10.05 ± 26.15). T1ρ PC4 was significantly correlated with HOOSsport , HOOSsymptoms , HOOSpain , HOOSadl , and HOOSqol at 2-year follow-up (ρ: [0.36, 0.50]). T1ρ PC2 and PC4 were significantly correlated with 30-second chair test (ρ = -0.39 and ρ = 0.24, respectively) and side plank (ρ = -0.32 and ρ = 0.21). T1ρ and T2 PC2 were significantly correlated with 40 m walk test (ρ = 0.34 and ρ = 0.31) and 30-second chair rise test (ρ = -0.39 and ρ = -0.32).

DATA CONCLUSION

Men exhibited accelerated T1ρ increases across the femoral cartilage compared to women, suggesting sex should be considered when evaluating early hip OA. Participants with poorer HOOS and function exhibited greater T1ρ and T2 increases in superior and anterior femoral cartilage and greater T1ρ increases in the anterior femoral cartilage. These patterns of short-term relaxometry increases could indicate hip OA progression.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 3.

Obesity defined molecular endotypes in the synovium of patients with osteoarthritis provides a rationale for therapeutic targeting of fibroblast subsets

BACKGROUND

Osteoarthritis (OA), a multifaceted condition, poses a significant challenge for the successful clinical development of therapeutics due to heterogeneity. However, classifying molecular endotypes of OA pathogenesis could provide invaluable phenotype-directed routes for stratifying subgroups of patients for targeted therapeutics, leading to greater chances of success in trials. This study establishes endotypes in OA soft joint tissue driven by obesity in both load-bearing and non-load bearing joints.

METHODS

Hand, hip, knee and foot joint synovial tissue was obtained from OA patients (n = 32) classified as obese (BMI > 30) or normal weight (BMI 18.5-24.9). Isolated fibroblasts (OA SF) were assayed by Olink proteomic panel, seahorse metabolic flux assay, Illumina's NextSeq 500 bulk and Chromium 10X single cell RNA-sequencing, validated by Luminex and immunofluorescence.

RESULTS

Targeted proteomic, metabolic and transcriptomic analysis found the inflammatory landscape of OA SFs are independently impacted by obesity, joint loading and anatomical site with significant heterogeneity between obese and normal weight patients, confirmed by bulk RNAseq. Further investigation by single cell RNAseq identified four functional molecular endotypes including obesity specific subsets defined by an inflammatory endotype related to immune cell regulation, fibroblast activation and inflammatory signaling, with up-regulated CXCL12, CFD and CHI3L1 expression. Luminex confirmed elevated chitase3-like-1(229.5 vs. 49.5 ng/ml, p < .05) and inhibin (20.6 vs. 63.8 pg/ml, p < .05) in obese and normal weight OA SFs, respectively. Lastly, we find SF subsets in obese patients spatially localise in sublining and lining layers of OA synovium and can be distinguished by differential expression of the transcriptional regulators MYC and FOS.

CONCLUSION

These findings demonstrate the significance of obesity in changing the inflammatory landscape of synovial fibroblasts in both load bearing and non-load bearing joints. Describing multiple heterogeneous OA SF populations characterised by specific molecular endotypes, which drive heterogeneity in OA disease pathogenesis. These molecular endotypes may provide a route for the stratification of patients in clinical trials, providing a rational for the therapeutic targeting of specific SF subsets in specific patient populations with arthritic conditions.

Association Between Metabolically Different Adiposity Subtypes and Osteoarthritis: A Mendelian Randomization Study

OBJECTIVE

In this Mendelian randomization (MR) study, the objective was to investigate the causal effect of metabolically different adiposity subtypes on osteoarthritis.

METHODS

We performed 2-sample MR using summary-level data for osteoarthritis (10,083 cases and 40,425 controls) from a genome-wide association using the UK Biobank, and for site-specific osteoarthritis from the Arthritis Research UK Osteoarthritis Genetics consortium. We used 3 classes of genetic instruments, which all increase body mass index but are associated with different metabolic profiles (unfavorable, neutral, and favorable). Primary analysis was performed using inverse variance weight (IVW), with additional sensitivity analysis from different MR methods. We further applied a nonlinear MR using UK Biobank data to understand the nature of the adiposity-osteoarthritis relationship.

RESULTS

Greater metabolically unfavorable and metabolically neutral adiposity were associated with higher odds of osteoarthritis (IVW odds ratio [OR] 1.56 [95% confidence interval (95% CI) 1.31, 1.85] and OR 1.60 [95% CI 1.15, 2.23], respectively). The estimate for the association between metabolically favorable adiposity and osteoarthritis was similar, although with notable imprecision (OR 1.55 [95% CI 0.70, 3.41]). Using site-specific osteoarthritis, metabolically unfavorable, neutral, and favorable adiposity were all associated with higher odds of knee osteoarthritis (OR 1.44 [95% CI 1.04, 1.98], OR 2.28 [95% CI 1.04, 4.99], and OR 6.80 [95% CI 2.08, 22.19], respectively). We found generally consistent estimates with a wider confidence interval crossing the null from other MR methods. The nonlinear MR analyses suggested a nonlinear relationship between metabolically unfavorable adiposity and osteoarthritis (Pnonlinear  = 0.003).

CONCLUSION

Metabolic abnormalities did not explain the association between greater adiposity and the risk of osteoarthritis, which might suggest that the association is largely due to a mechanical effect on the joints.

A sex- and site-specific relationship between body mass index and osteoarthritis: evidence from observational and genetic analyses

OBJECTIVE

We primarily aimed to investigate whether there are phenotypic and genetic links underlying body mass index (BMI) and overall osteoarthritis (OA). We then intended to explore whether the relationships differ across sexes and sites.

METHOD

We first evaluated the phenotypic association between BMI and overall OA using data from the UK Biobank. We then investigated the genetic relationship leveraging summary statistics of the hitherto largest genome-wide association studies performed for BMI and overall OA. Finally, we repeated all analyses in a sex- (female, male) and site- (knee, hip, spine) specific manner.

RESULTS

Observational analysis suggested an increased hazard of diagnosed OA per 5 kg/m² increment in BMI (hazard ratio = 1.38, 95% confidence interval (CI) = 1.37-1.39). A positive overall genetic correlation was observed for BMI and OA (r_g = 0.43, P = 4.72 × 10^-133), corroborated by 11 significant local signals. Cross-trait meta-analysis identified 34 pleiotropic loci shared between BMI and OA, of which seven were novel. Transcriptome-wide association study revealed 29 shared gene-tissue pairs, targeting nervous, digestive, and exo/endocrine systems. Mendelian randomization demonstrated a robust BMI-OA causal relationship (odds ratio = 1.47, 95% CI = 1.42-1.52). A similar pattern of effects was observed in sex- and site-specific analyses, with BMI affecting OA comparably in both sexes and most strongly in the knee.

CONCLUSION

Our work demonstrates an intrinsic relationship underlying BMI and overall OA, reflected by a pronounced phenotypic association, significant biological pleiotropy, and a putative causal link. Stratified analysis further reveals that the effects are distinct across sites and comparable across sexes.

Genetically predicted obesity and risk of hip osteoarthritis

OBJECTIVES

To determine the causal association between genetically predicted obesity and the risk of hip osteoarthritis.

METHODS

We performed two-sample Mendelian randomization (MR) analysis to analyze the association between body mass index (BMI) and hip osteoarthritis using pooled-level genome-wide association study (GWAS) data. The inverse variance weighted (IVW), MR‒Egger, and weighted median methods were used to estimate the causal association. In addition, we applied the MR Steiger filtering method, MR robust adjusted profile score (MR.RAPS) methods, and the MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) global test to examine and address potential horizontal pleiotropy.

RESULTS

We found a causal relationship between genetically predicted BMI and the risk of hip osteoarthritis by the IVW method [OR = 1.45, 95% confidence interval (CI) = 1.04-2.00, P = 0.02]. In the sensitivity analysis, the results of the MR‒Egger and weighted median methods revealed similar estimations but with a wide CI with lower precision. The funnel plot, MR-Egger intercept, and MR-PRESSO all indicated the absence of a directional pleiotropic effect. In addition, no heterogeneity was observed in the present analysis. Therefore, the result of IVW is most suitable and reliable for the present MR analysis.

CONCLUSION

There is a causal relationship between obesity and a higher risk of hip osteoarthritis, suggesting that weight management may be an intervention for the prevention and management of hip osteoarthritis.

LEVEL OF EVIDENCE

Bioinformatics, Basic science.

An Updated Approach to Antiobesity Pharmacotherapy: Moving Beyond the 5% Weight Loss Goal

Despite professional society guidelines recommending that obesity be treated as a chronic disease by emphasizing the use of lifestyle modification in conjunction with pharmacotherapy, antiobesity medications are uncommonly prescribed in most clinical practices. The recent Food and Drug Administration approval of semaglutide 2.4 mg weekly to treat obesity-as well as other forthcoming advancements in diabetes and antiobesity medications-highlights the potential of pharmacotherapy to significantly augment weight loss efforts. In this Expert Endocrine Consult, we review the evolving role of antiobesity pharmacotherapy in clinical practice and suggest a framework for the use of these medications.

Incidence and risk factors of postoperative nausea and vomiting following laparoscopic sleeve gastrectomy and its relationship with Helicobacter pylori: A propensity score matching analysis

BACKGROUND

Postoperative nausea and vomiting (PONV) are common after laparoscopic sleeve gastrectomy (LSG), affecting patient satisfaction and postoperative recovery. The purpose of this study was to investigate the incidence and severity of PONV after LSG and the relationship between Helicobacter pylori (HP) and PONV.

METHODS

Patients undergoing LSG in our center from June 1, 2018, to May 31, 2022, were divided into HP-positive and HP-negative groups for retrospective analysis. The independent risk factors of PONV were determined by univariate and binary logistic regression analysis using a 1:1 propensity score matching (PSM) method.

RESULTS

A total of 656 patients was enrolled, and 193 pairs of HP-positive and negative groups were matched after PSM. Both groups of patients had similar clinical features and surgical procedures. PONV occurred in 232 patients (60.1%) after LSG, and the incidence of PONV in HP-positive patients was 61.10%. The incidence and severity of PONV were statistically similar in both groups (P=0.815). Multivariate analysis showed that the female sex (OR=1.644, P=0.042), postoperative pain (OR=2.203, P=0.001) and use of postoperative opioid (OR=2.229, P=0.000) were independent risk factors for PONV after LSG, whereas T2DM (OR=0.510, P=0.009) and OSAS (OR=0.545, P=0.008) independently reduced the incidence rate of PONV. There was no difference either in smoking (P=0.255) or alcohol drinking (P=0.801). HP infection did not affect PONV (P=0.678).

CONCLUSIONS

The incidence of PONV following LSG was relatively high. Female sex, postoperative pain and use of postoperative opioid predicted a higher incidence of PONV. Patients with T2DM and OSAS were less likely to have PONV. There was no clear association between HP infection and PONV after LSG.

Which hip morphology measures and patient factors are associated with age of onset and symptom severity in femoroacetabular impingement syndrome?

BACKGROUND

Bony morphology is central to the pathomechanism of femoroacetabular impingement syndrome (FAIS), however isolated radiographic measures poorly predict symptom onset and severity. More comprehensive morphology measurement considered together with patient factors may better predict symptom presentation. This study aimed to determine the morphological parameter(s) and patient factor(s) associated with symptom age of onset and severity in FAIS.

METHODS

99 participants (age 32.9 ± 10.5 years; body mass index (BMI 24.3 ± 3.1 kg/m²; 42% females) diagnosed with FAIS received standardised plain radiographs and magnetic resonance scans. Alpha angle in four radial planes (superior to anterior), acetabular version (AV), femoral torsion, lateral centre-edge, anterior centre-edge (ACEA) and femoral neck-shaft angles were measured. Age of symptom onset (age at presentation minus duration of symptoms), international Hip Outcome Tool-33 (iHOT-33) and modified UCLA activity scores were recorded. Backward stepwise regression assessed morphological parameters and patient factors (age, sex, BMI, symptom duration, annual income, private/public healthcare system accessed) to determine variables independently associated with onset age and iHOT-33 score.

RESULTS

Earlier symptom onset was associated with larger superoanterior alpha angle (p = 0.007), smaller AV (p = 0.023), lower BMI (p = 0.010) and public healthcare system access (p = 0.041) (r² = 0.320). Worse iHOT-33 score was associated with smaller ACEA (p = 0.034), female sex (p = 0.040), worse modified UCLA activity score (p = 0.010) and public healthcare system access (p < 0.001) (r² = 0.340).

CONCLUSIONS

Age of symptom onset was chiefly predicted by femoral and acetabular bony morphology measures, whereas symptom severity predominantly by patient factors. Factors measured explained a small amount of variance in the data; additional unmeasured factors may be more influential.

The economic impact of obesity in Kuwait: a micro-costing study evaluating the burden of obesity-related comorbidities

OBJECTIVE

44% of Kuwait's population live with obesity and the health consequences place a significant burden on the public health system. This study provides an assessment of the cost burden of obesity-related comorbidities (ORC).

METHODS

A retrospective micro-costing analysis was conducted to quantify the direct cost associated with ORCs. ORCs and their cost categories were informed by a systematic literature review and validated by a local steering committee comprising three experts. Seventy public sector clinicians and eight hospital procurement staff were surveyed to provide healthcare resource utilization estimates and medical resource cost data, respectively. The annual cost of each ORC and the cost drivers were also validated by the steering committee.

RESULTS

Individuals in Kuwait with any single ORC incurred direct healthcare costs ranging 1,748-4,205 KWD annually. Asthma, chronic kidney disease and type 2 diabetes were the costliest ORCs, incurring an annual cost that exceeds 3,500 KWD per patient. Hypertension, angina and atrial fibrillation were the least costly ORCs. In general, costs were driven by drug costs and resources allocated to address treatment-related adverse events.

LIMITATIONS

In the absence of an official patient registry in Kuwait, our study provides a conservative estimate of direct costs derived from a nationwide survey. Additionally, the cost estimates in this study assumes that a patient with obesity will only experience one ORC. In reality, multi-morbid states may incur additional costs that are not currently captured.

CONCLUSIONS

Our study confirms that ORCs generate a significant financial burden to the public payer. The study provides an economic case for policymakers to recognize the exigency for obesity prevention and control in accordance with the ORC prevalence, and the need for sustainable investments towards body-mass index management to prevent individuals from developing multiple comorbidities.

Management of obesity across women's life course: FIGO Best Practice Advice

Obesity is a chronic, progressive, relapsing, and treatable multifactorial, neurobehavioral disease. According to the World Health Organization, obesity affects 15% of women and has long-term effects on women's health. The focus of care in patients with obesity should be on optimizing health outcomes rather than on weight loss. Appropriate and common language, considering cultural sensitivity and trauma-informed care, is needed to discuss obesity. Pregnancy is a time of significant physiological change. Pre-, ante-, and postpartum clinical encounters provide opportunities for health optimization for parents with obesity in terms of, but not limited to, fertility and breastfeeding. Pre-existing conditions may also be identified and managed. Beyond pregnancy, women with obesity are at an increased risk for gastrointestinal and liver diseases, impaired kidney function, obstructive sleep apnea, and venous thromboembolism. Gynecological and reproductive health of women living with obesity cannot be dismissed, with accommodations needed for preventive health screenings and consideration of increased risk for gynecologic malignancies. Mental wellness, specifically depression, should be screened and managed appropriately. Obesity is a complex condition and is increasing in prevalence with failure of public health interventions to achieve significant decrease. Future research efforts should focus on interprofessional care and discovering effective interventions for health optimization.

A causal relationship between childhood obesity and risk of osteoarthritis: results from a two-sample Mendelian randomization analysis

PURPOSE

It has been found that childhood obesity (CO) may play an important role in the onset and progression of osteoarthritis (OA). Thus we conducted this mendelian randomisation analysis (MR) to evaluate the causal association between childhood obesity and osteoarthritis.

METHODS

Instrumental variables (IVs) were obtained from publicly available genome-wide association study datasets. The leave-one-out sensitivity test, MR Pleiotropy RESidual Sum and Outlier test (MR-PRESSO), and Cochran's Q test were used to confirm the heterogeneity and pleiotropy of identified IVs, then five different models, including the inverse variance weighted model (IVW), weighted median estimator model (WME), weighted model-based method (WM), MR-Egger regression model (MER), and MR-Robust Adjusted Profile Score (MRAPS) were applied in this MR analysis.

RESULTS

After excluding all outliers identified by the MR-PRESSO test, no evident directional pleiotropy was found. Significant heterogeneity was found in the secondary MR and as a result, the multiplicative random-effect model was used. Significant causal association between CO and OA (OR 1.0075, 95% CI [1.0054, 1.0010], p = 8.12 × 10^-13). The secondary MR also revealed that CO was causally associated with knee OA (OR 1.1067, 95% CI [1.0769, 1.1373], p = 3.30 × 10^-13) and hip OA (OR 1.1272, 95% CI [1.0610, 1.1976], p = 1.07 × 10^-4). The accuracy and robustness of these findings were confirmed by sensitivity tests.

CONCLUSION

There appears to be a causal relationship between childhood obesity and OA. Our results indicate that individuals with a history of childhood obesity require specific clinical attention to prevent the development of knee and hip OA.

Postoperative Inpatient Rehabilitation Does Not Increase Knee Function after Primary Total Knee Arthroplasty

Inpatient rehabilitation (IR) is a common postoperative protocol after total knee replacement (TKA). Because IR is expensive and should therefore be justified, this study determined the difference in knee function one year after TKA in patients treated with IR or outpatient rehabilitation, fast-track rehabilitation (FTR) in particular, which also entails a reduced hospital length of stay. A total of 205 patients were included in this multi-center prospective cohort study. Of the patients, 104 had primary TKA at a German university hospital and received IR, while 101 had primary TKA at a Canadian university hospital and received FTR. Patients receiving IR or FTR were matched by pre-operative demographics and knee function. Oxford Knee Score (OKS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and EuroQol visual analogue scale (EQ-VAS) determined knee function one year after surgery. Patients receiving IR had a 2.8-point lower improvement in OKS (p = 0.001), a 6.7-point lower improvement in WOMAC (p = 0.063), and a 12.3-point higher improvement in EQ-VAS (p = 0.281) than patients receiving FTR. IR does not provide long-term benefits to patient recovery after primary uncomplicated TKA under the current rehabilitation regime.

Optimal BMI cutoff points in obesity screening for Chinese college students

Objective

An accurate BMI classification system specific to the population is of great value in health promotion. Existing studies have shown that the BMI recommended cut-off value for adults is not suitable for college students. Thus, the current study aims to identify optimal BMI cutoff points in obesity screening for Chinese college students.

Methods

Anthropometric assessments were performed on 6,798 college students (Male = 3,408, Female = 3,390) from three universities in Jiangsu, China. Exploratory factor analysis (EFA) was conducted to establish the standardized models to estimate anthropometry for male and female students. Further indices were derived from the assessments, including body mass index (BMI), relative fat mass (RFM), obesity degree percentage (OBD%), waist-to-hip ratio (WHR), waist circumference (WC), and body fat percentage (BF%). The anthropometric index with the highest correlation to the models for male and female students were selected as the gold standard for obesity screening. Receiver operating characteristic (ROC) curve was applied to evaluate diagnostic value of each anthropometric index according to the area under curve (AUC). Youden index maximum points determined the optimal cutoff points with the highest accuracy in obesity screening.

Results

The anthropometric models for both male and female students consisted of three factors. Vervaeck index was selected as the gold standard for obesity screening. By comparing AUC of the anthropometric indices, we found BMI provided the highest value in obesity screening. Further analysis based on Youden index identified the optimal BMI of 23.53 kg/m² for male and 23.41 kg/m² for female. Compared with the universal standard recommended by World Health Organization (WHO), the adjusted BMI criteria were characterized by high sensitivity as well as specificity.

Conclusion

BMI is the most appropriate anthropometric index of obesity screening for Chinese college students. The optimal cutoff points were lower than the WHO reference. Evidence substantiated the adjusted BMI criteria as an effective approach to improve accuracy of obesity screening for this population.

Famine exposure in adolescence is associated with a higher risk of overweight/obesity and abdominal obesity in adulthood: A meta-analysis

Some studies have shown that famine exposure during adolescence can increase cardiovascular disease and diabetes susceptibility in later life. The association between famine exposure in adolescence and overweight/obesity and abdominal obesity in adulthood has been inconsistent. Based on previous studies, we hypothesized that famine exposure in adolescence increases the risk of overweight/obesity and abdominal obesity in adulthood. Eight databases, including PubMed, Embase, Cochrane Library, and Web of Science, were searched from their inception until November 2021. We initially identified 3982 records and finally included 7 articles after screening. The included articles were of moderate to high quality, containing 16 estimates of overweight/obesity and 3 estimates of abdominal obesity. Pooled odds ratios (ORs) with 95% CIs were used to estimate the association between them. The random effects model was adopted as the pooling method. There was a significant association between famine exposure in adolescence and overweight/obesity in adulthood (OR, 1.17; 95% CI, 1.02-1.33). Adolescents exposed to famine had a greater risk of abdominal obesity in adulthood than their unexposed counterparts (OR, 1.35; 95% CI, 1.03-1.76). These results were more pronounced in females than in males. In summary, our meta-analysis indicates that famine exposure during adolescence increases the risk of overweight/obesity and abdominal obesity in adulthood. This suggests that we need to pay timely attention to the nutritional status of adolescents to prevent adverse health consequences of malnutrition. More high-quality studies are needed to confirm these conclusions, given the limitations of this study.

Relationship Between Body Mass Index and Osteoarthritis for Single and Multisite Osteoarthritis of the Hand, Hip, or Knee: Findings From a Canadian Longitudinal Study on Aging

OBJECTIVE

To determine whether an apparent association between hand osteoarthritis (OA) and adiposity is explained by the presence of OA at other joint sites.

METHODS

Data from the Canadian Longitudinal Study on Aging, first cycle, comprehensive cohort, were used. Respondents age 45-85 years (n = 18,279) were asked separate questions about doctor-diagnosed OA in the hand, hip, or knee. Multinomial logistic regression was used to investigate the relationship between all combinations of hand, hip, and knee OA and body mass index (BMI) and waist-to-height ratio (WHtR).

RESULTS

OA was reported by 34.6% of respondents, 28.0% with OA at >1 joint site. Hand OA was not significantly associated with BMI after accounting for OA at other joint sites, with similar findings for WHtR. All joint site combinations containing the knee were strongly associated with BMI, with odds ratios (ORs) ranging from OR 2.92 (95% confidence interval [95% CI] 2.53-3.37) for knee OA only with obesity class I to OR 9.98 (95% CI 7.12-13.88) for multi-joint knee, hip, hand OA with obesity class II/III. BMI distributions including knee OA were broader and shifted to higher BMI levels than those for hand or hip OA.

CONCLUSION

Apparent associations between hand OA and BMI may be explained by concurrent OA at other joint sites. Recognizing that OA is a multi-joint disease is crucial for studies of the associations of adiposity with OA in a particular joint, especially the hand. The association between knee OA and BMI appears to be distinct from those for OA at other joint sites.

Causal associations of obesity related anthropometric indicators and body compositions with knee and hip arthritis: A large-scale genetic correlation study

Backgrounds

Epidemiological studies have repeatedly investigated the association between obesity related anthropometric indicators and body compositions and osteoarthritis (OA). However, the results have remained inconsistent. This work aimed to investigate the genetic correlation and causal associations of obesity related anthropometric indicators and body compositions with knee and hip OA.

Methods

Single-nucleotide polymorphisms associated with the exposures were searched from the recent genome-wide association studies (GWAS) to obtain full statistics. Summary-level results of knee and hip OA were from the UK Biobank and arcOGEN. First, linkage disequilibrium score regression (LD score regression) was applied to detect the genetic correlation (rg). We further performed a series of sensitivity analyses as validation of primary mendelian randomization (MR) results and the specific evidence of potential causal effects was defined.

Results

We found that genetic components in OA had significant correlation with obesity related traits, except waist-to-hip ratio. In the univariable MR analysis, with the exception of waist-to-hip ratio, obesity related anthropometric indicators were causally associated with increased risks of knee and hip OA. For obesity related body compositions, higher fat-free mass in arm, leg, and whole body increased the risk of knee OA but only fat-free mass in leg showed a significant association with hip OA. Meanwhile trunk fat mass and trunk fat percentage, were associated with knee but not with hip OA. Higher fat mass, and fat percentage in arm, leg, and whole body increased the risk of both knee and hip OA. After adjusting for BMI, the multivariable MR showed maintained results in knee OA. However, in hip OA, only fat mass and fat-free mass in arm, leg, trunk and whole body were significantly associated with the risk of hip OA.

Conclusion

The present study suggests genetic evidence for certain causal associations of obesity related anthropometric indicators and body compositions with knee and hip OA, which may provide important insights for the prevention and treatment on OA.

Influence of physically demanding occupations on the development of osteoarthritis of the hip: a systematic review

Background

Hip osteoarthritis (HOA) is a disabling disease affecting around 33 million people worldwide. People of working age and the elderly are at increased risk of developing HOA and the disease is associated with high costs at individual and societal levels due to sick leaves, job loss, total hip replacements and disability pension. This systematic review evaluated the influence of physically demanding occupations on the development of HOA in men.

Methods

Cohort studies, case–control studies and cross-sectional studies with publications in English or German, which assessed the association between exposure to physically demanding occupations and development of HOA, were searched in electronic databases (Medline, Embase, HSE-Line, Cochrane Library) and conference abstracts from 1990 until May 2020. We assessed the methodological quality of selected studies, interpreted all relative effect estimators as relative risks (RRs) and meta-analytically reviewed the effects of occupations with high physical workloads. All steps are based on a study protocol published in PROSPERO (CRD42015016894).

Results

Seven cohort studies and six case–control studies were included. An elevated risk to develop HOA was shown for six physically demanding occupational groups. Working in agriculture including fishery and forestry and food production doubles the risk of HOA. Construction, metal working and sales as well as exposure to whole body vibration while driving vehicles increases the risk by roughly 50 to 60%. Unskilled or basic level workers, who were frequently exposed to repetitive heavy manual work, had nearly a doubled risk (RR 1.89 95%CI: 1.29 to 2.77) compared to workers with lower exposure.

Conclusions

Existing studies state an association between various occupations with high physical workload and an increased risk of developing HOA. High Physical workloads include including lifting and carrying heavy loads, demanding postures, repetitive activities, long standing and running, as well as exposure to body vibrations. Occupational prevention and early detection as well as individual health promotion strategies should place their focus on reducing the impact of high physical strain at work sites.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12995-022-00358-y.

Recent insights into the role of microbiome in the pathogenesis of obesity

Obesity is a risk factor for many chronic diseases and its rising prevalence the last couple of decades is a healthcare concern in many countries. Obesity is a multifactorial problem that is not only limited in its causation by diet and lack of exercise. Genetics but also environmental factors such as the gut microbiome should similarly be taken into account. A plethora of articles have been published, that from various different angles, attempt to disentangle the complex interaction between gut microbiota and obesity. Examples range from the effect of the gut microbiota on the host immune system to the pathophysiological pathways in which microbial-derived metabolites affect obesity. Various discordant gut microbiota findings are a result of this complexity. In this review, in addition to summarizing the classical role of the gut microbiome in the pathogenesis of obesity, we attempt to view both the healthy and obesogenic effects of the gut microbiota as a consequence of the presence or absence of collective guilds/trophic networks. Lastly, we propose avenues and strategies for the future of gut microbiome research concerning obesity.

A 2022 update on the epidemiology of obesity and a call to action: as its twin COVID-19 pandemic appears to be receding, the obesity and dysmetabolism pandemic continues to rage on

The WHO just released in May 2022 a report on the state of the obesity pandemic in Europe, stating that 60% of citizens in the area of Europe are either overweight or obese, and highlighting the implications of the obesity pandemic, especially as it interacts with the COVID pandemic to create a twin pandemic, to increase morbidity and mortality. Obesity is a complex disease which has reached pandemic dimensions. The worldwide prevalence of obesity has nearly tripled since 1975, mainly due to the adoption of a progressively more sedentary lifestyle and the consumption of less healthy diets. We first report herein updated prevalence rates of overweight and obesity by sex, age, and region first in Europe, per the WHO report, and then worldwide between 1980 and 2019, as we analyze and present herein the data provided by the Global Burden of Disease Study. The prevalence of obesity is higher in women than in men of any age and the prevalence of both overweight and obesity increases with age and has reached their highest point between the ages of 50 to 65 years showing a slight downward trend afterwards. The age-standardized prevalence of obesity has increased from 4.6% in 1980 to 14.0% in 2019. The American and European region have the highest obesity prevalence and the USA and Russia are the countries with the most obese residents. Given dire implications in terms of comorbidities and mortality, these updated epidemiological findings call for coordinated actions from local and regional governments, the scientific community and individual patients alike, as well as the food industry for the obesity pandemic to be controlled and alleviated. We can hopefully learn from the COVID-19 pandemic, where collaborative efforts worldwide, focused intense work at both the local and global level and well-coordinated leadership have demonstrated that humankind is capable of amazing accomplishments by leveraging science and public health, and that we can finally make strides in terms of understanding and combating the obesity pandemic and its dire comorbidities including diabetes, NAFLD, CVD and obesity associated malignancies.

A narrative review of anti-obesity medications for obese patients with osteoarthritis

INTRODUCTION

: The prevalence of both obesity and osteoarthritis (OA) are increasing worldwide (twindemic), and the association between the two chronic diseases is also well-established.

AREAS COVERED

: In this narrative review, we will briefly describe the double burdens of both diseases, the impact of weight loss or gain on OA incidence and structural progression and discuss the biomechanical and anti-inflammatory mechanisms mediating these effects. FDA-approved anti-obesity drugs are summarized in terms of their clinical efficacy and safety profile, and the completed or ongoing phase 2/3 clinical trials of such drugs in OA patients with obesity are examined.

EXPERT OPINION

: We will discuss the perspectives related to principles of prescription of anti-obesity drugs, the potential role of phenotype-guided approach, time to drug effects in clinical trials, sustainability of weight loss based on the real-world studies, the importance of concomitant therapies such as dieting and exercises, and the role of weight loss on non-weight bearing OA joints. Although obesity is the major risk factor for OA pathogenesis and progression, and there are a variety of anti-obesity medications on the market, research on the use of these disease-modifying drugs in OA (DMOAD) is still sparse..

What Is the Impact of Body Mass Index Cutoffs on Total Hip Arthroplasty Complications?

BACKGROUND

Body mass index (BMI) cutoffs are commonly utilized to decide whether to offer obese patients elective total hip arthroplasty (THA). However, weight loss goals may be unachievable for many, and some patients are thereby denied complication-free surgery. The purpose of this study was to assess the impact of varying BMI cutoffs on the rates of complication-free surgery after THA.

METHODS

Patients undergoing THA between 2015 and 2018 were identified in the American College of Surgeons National Surgical Quality Improvement Program database using Common Procedural Terminology code 27130. BMI and rates of 30-day complications were collected. BMI cutoffs of 30, 35, 40, 45, and 50 kg/m² were applied to model the incidence of complications if THA would have been allowed to proceed based on BMI.

RESULTS

A total of 192,394 patients underwent THA, and 13,970 (7%) of them had a BMI ≥40 kg/m². With a BMI cutoff of 40 kg/m², 178,424 (92.7%) patients would have proceeded with THA. From this set, 170,296 (95.4%) would experience complication-free surgery, and 11.8% of complications would be prevented. THA would proceed for 191,217 (99.3%) patients at a BMI cutoff of 50 kg/m², of which 182,123 (95.2%) would not experience a complication, and 1.3% of complications would be prevented. Using 35 kg/m² as the BMI cutoff would prevent 28.6% of complications and permit 75.9% of complication-free surgeries to proceed.

CONCLUSION

Lower BMI cutoffs for THA can result in fewer complications although they will consequentially limit access to complication-free THA. Consideration of risks of obesity in THA may be best considered as part of a holistic assessment and shared decision-making when deciding on goals for weight reduction.

Preoperative preparation and premedication of bariatric surgical patient

The prevalence of obesity has tripled worldwide over the past four decades. The United States has the highest rates of obesity, with 88% of the population being overweight and 36% obese. The UK has the sixth highest prevalence of obesity. The problem of obesity is not isolated to the developed world and has increasingly become an issue in the developing world as well. Obesity carries an increased risk of many serious diseases and health conditions, including type 2 diabetes, heart disease, stroke, sleep apnea, and certain cancers. Our ability to take care of this population safely throughout the perioperative period begins with a thorough and in-depth preoperative assessment and meticulous preparation. The preoperative assessment begins with being able to identify patients who suffer from obesity by using diagnostic criteria and, furthermore, being able to identify patients whose obesity is causing pathologic and physiologic changes. A detailed and thorough anesthesia assessment should be performed, and the anesthesia plan individualized and tailored to the specific patient's risk factors and comorbidities. The important components of the preoperative anesthesia assessment and patient preparation in the patient suffering from obesity include history and physical examination, airway assessment, medical comorbidities evaluation, functional status determination, risk assessment, preoperative testing, current weight loss medication, and review of any prior weight loss surgeries and their implications on the upcoming anesthetic. The preoperative evaluation of this population should occur with sufficient time before the planned operation to allow for modifications of the preoperative management without needing to delay surgery as the perioperative management of patients suffering from obesity presents significant practical and organizational challenges.

Point prevalence of Hip Symptoms, Radiographic, And Symptomatic OA at Five Time Points: The Johnston County Osteoarthritis Project, 1991-2018

Objective

To describe the point prevalence of hip symptoms, radiographic hip osteoarthritis (rHOA), severe rHOA, and symptomatic rHOA (sxHOA) at five time points in the longitudinal, population-based Johnston County Osteoarthritis Project (JoCoOA).

Design

Data were from 3068 JoCoOA participants who attended up to five study visits (1991-2018). Standardized supine pelvis radiographs were read by a single, expert musculoskeletal radiologist with high reliability. The four outcomes were: 1) self-reported hip symptoms: "On most days, do you have pain, aching, or stiffness in your right/left hip?"; 2) rHOA: Kellgren-Lawrence grade (KLG) of 2-4; 3) severe rHOA: KLG of 3-4; and 4) sxHOA: both symptoms and rHOA in the same joint. Weighted point prevalence and 95% confidence intervals (CI) were generated overall and by age group (45-54, 55-64, 65-74, 75+ years), sex, race (Black/White), and body mass index (BMI; 18.5-24.9; 25-29.9; 30+ kg/m2).

Results

At the most recent follow-up (2017-2018), the point prevalence (%) of hip symptoms, rHOA, severe rHOA, and sxHOA were 30% (95% CI 25%, 35%), 53% (95% CI 48%, 58%), 9% (95% CI 6%, 12%), and 15% (95% CI 11%, 19%), respectively. RHOA and severe rHOA were most prevalent in those 75+ years. Women were more likely than men to have hip symptoms and sxHOA. No consistent trends were noted by race or BMI.

Conclusion

These updated point prevalence estimates demonstrate a large and increasing burden of HOA in the general population, particularly with aging. Black and White individuals were affected similarly in this cohort.

Spectral-domain OCT measurements in obesity: A systematic review and meta-analysis

Background

Previous studies proposed possible applications of spectral-domain optical coherence tomography (SD-OCT) measurements in prognosticating pathologies observed in overweight/obesity, including ocular, vascular, and neurologic consequences. Therefore, we conducted a systematic review and meta-analysis to investigate the changes in the in SD-OCT measurements of the patients with higher body mass index (BMI) compared to normal weight individuals.

Materials and methods

We conducted a systematic search on PubMed, Scopus, and Embase. The search results underwent two-phase title/abstract and full-text screenings. We then analyzed SD-OCT measurements differences in patients with high BMI and controls, and performed meta-regression, sub-group analysis, quality assessment, and publication bias assessment. The measurements included macular thickness, cup to disc ratio, ganglion cell-inner plexiform layer (GC-IPL) and its sub-sectors, RNFL and peripapillary RNFL (pRNFL) and their sub-layers, and choroidal thickness and its sub-sectors.

Results

19 studies were included in this meta-analysis accounting for 1813 individuals, 989 cases and 824 controls. There was an overall trend towards decreased thickness in high BMI patients, but only two measurements reached statistical significance: temporal retinal nerve fiber layer (RNFL) (Standardized mean difference (SMD): -0.33, 95% confidence interval (CI): -0.53 to -0.14, p<0.01) and the choroidal region 1.0 mm nasal to fovea (SMD: -0.38, 95% CI: -0.60 to -0.16, p<0.01).

Conclusion

Some ocular layers are thinner in patients with higher BMI than the controls. These SD-OCT measurements might correlate with adverse events related to increased body weight and have prognostic abilities. As SD-OCT is a robust, rapid and non-invasive tool, future guidelines and studies are needed to evaluate the possibility of their integration into care of the patients with obesity.

Intermittent Fasting versus Continuous Calorie Restriction: Which Is Better for Weight Loss?

We conducted a systematic review and meta-analysis of randomized clinical trials and pilot trial studies to compare the effectiveness of intermittent fasting (IF) and continuous calorie restriction (CCR) in overweight and obese people. The parameters included body mass index (BMI), body weight, and other metabolism-related indicators. A systematic search in PubMed, Embase, Cochrane Library, and Web of Science was conducted up to January 2022. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were used to measure the effectiveness. Publication bias was assessed using Egger’s test. The stability of the results was evaluated using sensitivity analyses. The significance of body weight change (SMD = −0.21, 95% CI (−0.40, −0.02) p = 0.028) was more significant after IF than CCR. There was no significant difference in BMI (SMD = 0.02, 95% CI (−0.16, 0.20) p = 0.848) between IF and CCR. These findings suggest that IF may be superior to CCR for weight loss in some respects.

The correlation of 25-hydroxyvitamin D with BMI and lipid profile: A retrospective cohort study of Syrian patients

Background

This study aims to identify the prevalence of 25OHD deficiency in Syrian patients and investigate the relationship with obesity and lipid profile.

Methods

A retrospective cohort study consisted of 201 patients of age >10 years, who referred to Al Assad and Al Mouwasat University Hospitals, Damascus, Syria from Oct/2020 to Oct/2021. The data was analyzed by using linear regressions and produced a matrix of correlations with significant equations between study variables.

Results

Firstly, participants were divided depending on 25OHD levels, where 92.5% of patients had 25OHD <30 ng/mL. Inverse correlation between 25OHD and BMI (P ≤ 0.001) was observed, where severe 25OHD deficiency group had higher BMI (27.40 ± 7.22 kg/m2) and higher levels of Chol (211 ± 67.12 mg/dl) than in sufficiency group.Secondly, participants were divided depending on BMI. Higher BMI associated with lower levels of 25OHD. Moreover, we derived that every increase in 25OHD by 1 ng/mL results in decrease of BMI by 0.26 kg/m2 (P ≤ 0.001) and results in decrease of Chol by 1.54 mg/dl (P ≤ 0.004).

Conclusion

A high prevalence of 25OHD deficiency was observed in this sample of Syrian patients. There is an inverse correlation between 25OHD and BMI regardless of age and gender. Moreover, the equation, that derived between 25OHD and BMI, represents a beneficial and an inexpensive tool in clinical practice to minimize testing of 25OHD by predicting its deficiency based on BMI and supports the impact of 25OHD supplementation for reduce BMI.

The effect of body mass index on blood loss and complications in simultaneous bilateral total hip arthroplasty: A multicenter retrospective study

BACKGROUND

The effect of body mass index (BMI) on blood loss in simultaneous bilateral total hip arthroplasty (SBTHA) was still undetermined. The purpose of the study was to evaluate the blood loss, transfusion and incidence of complications in normal, overweight, and obese patients undergoing SBTHA.

METHODS

A total of 344 patients following SBTHA were enrolled into this study. The patients were assigned into three groups on the basis of their BMI, including normal (BMI 18.0-24.9 kg/ m2), overweight (BMI 25.0-29.9 kg/ m2), or obese group (BMI ≥ 30.0 kg/ m2). The primary outcome was total blood loss (TBL), and secondary outcomes were intraoperative blood loss, drain volume, ratio of TBL and patient's blood volume (PBV), transfusion rate and volume, hemoglobin and hematocrit drop, length of stay, expenses, and complications.

RESULTS

The PBV and TBL increased significantly along with the elevated BMI (p < 0.001; p = 0.019, respectively). There was no significant difference in intraoperative blood loss, drain volume, transfusion volume, length of stay, expenses, or incidence of complications among the three groups. In addition, the transfusion rate in normal group was higher than that in overweight (58.3% vs 39.6%, p = 0.001) and obese group (58.3% vs 31.9%, p = 0.001). The maximum hemoglobin drop in obese group was the highest (p = 0.001).

CONCLUSION

Obesity could increase perioperative blood loss but not increase transfusion risk in the setting of SBTHA. Conversely, obese and overweight patients maybe have lower transfusion need compared with normal patients because of more blood volume. In addition, obesity did not affect the incidence of complications.

Differential Metabotypes in Synovial Fibroblasts and Synovial Fluid in Hip Osteoarthritis Patients Support Inflammatory Responses

Changes in cellular metabolism have been implicated in mediating the activated fibroblast phenotype in a number of chronic inflammatory disorders, including pulmonary fibrosis, renal disease and rheumatoid arthritis. The aim of this study was therefore to characterise the metabolic profile of synovial joint fluid and synovial fibroblasts under both basal and inflammatory conditions in a cohort of obese and normal-weight hip OA patients. Furthermore, we sought to ascertain whether modulation of a metabolic pathway in OA synovial fibroblasts could alter their inflammatory activity. Synovium and synovial fluid was obtained from hip OA patients, who were either of normal-weight or obese and were undergoing elective joint replacement surgery. The synovial fluid metabolome was determined by 1H NMR spectroscopy. The metabolic profile of isolated synovial fibroblasts in vitro was characterised by lactate secretion, oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) using the Seahorse XF Analyser. The effects of a small molecule pharmacological inhibitor and siRNA targeted at glutaminase-1 (GLS1) were assessed to probe the role of glutamine metabolism in OA synovial fibroblast function. Obese OA patient synovial fluid (n = 5) exhibited a different metabotype, compared to normal-weight patient fluid (n = 6), with significantly increased levels of 1, 3-dimethylurate, N-Nitrosodimethylamine, succinate, tyrosine, pyruvate, glucose, glycine and lactate, and enrichment of the glutamine-glutamate metabolic pathway, which correlated with increasing adiposity. In vitro, isolated obese OA fibroblasts exhibited greater basal lactate secretion and aerobic glycolysis, and increased mitochondrial respiration when stimulated with pro-inflammatory cytokine TNFα, compared to fibroblasts from normal-weight patients. Inhibition of GLS1 attenuated the TNFα-induced expression and secretion of IL-6 in OA synovial fibroblasts. These findings suggest that altered cellular metabolism underpins the inflammatory phenotype of OA fibroblasts, and that targeted inhibition of glutamine-glutamate metabolism may provide a route to reducing the pathological effects of joint inflammation in OA patients who are obese.

Hybrid Hyaluronic Acid versus High Molecular Weight Hyaluronic Acid for the Treatment of Hip Osteoarthritis in Overweight/Obese Patients

Background: Obesity is the main risk factor for hip osteoarthritis, negatively affecting the outcome of the disease. We evaluated the effectiveness of viscosupplementation with hybrid hyaluronic acid compared to that with high molecular weight hyaluronic acid in overweight/obese patients with hip osteoarthritis (OA). Methods: 80 patients were divided into two groups: a treatment group received two ultrasound-guided intra-articular hip injections of hybrid HA 15 days apart; a control group received a single ultrasound-guided infiltration with medium-high molecular weight hyaluronic acid (1500−2000 kDa). We assessed the pain, functional and cardiovascular capacity of the patients at baseline, after 3 months, and after 6 months of the infiltrative sessions. Results: The treatment group showed greater improvements in the scores on the NRS scale (5.4 ± 0.8 vs. 6.3 ± 0.8; p < 0.05) and in the Lequesne index (11.4 ± 2.6 vs. 13.6 ± 2.7; p < 0.05) and in the distance traveled at 6MWT (238.1 ± 53.9 m vs. 210.7 ± 46.2 m; p = 0.02) both at 3 months (T1) and at 6 months (T2). Conclusions: This study underlines the importance of exploiting the anti-inflammatory, analgesic, and chondrogenic properties of hybrid HA for the treatment of hip OA in overweight/obese patients.

Risk factors for long-term hip osteoarthritis in patients with hip dysplasia without surgical intervention

Hip dysplasia is a common cause of hip pain and a known risk factor for hip osteoarthritis (OA) and early total hip arthroplasty (THA). Unfortunately, little is known about the specific factors associated with an increased risk of OA. The purpose was (i) to report the overall rate of symptomatic hip OA and THA and (ii) to identify radiographic features and patient characteristics associated with the development of symptomatic hip OA. A geographic database was used to identify all patients aged 14–50 years old diagnosed with symptomatic hip dysplasia between 2000 and 2016. Kaplan–Meier analysis was used to determine the rate of symptomatic hip OA, defined as a Tönnis grade of ≥1 on hip radiograph. Univariate and multivariate proportional hazard regression models were performed to determine risk factors for OA. One hundred and fifty-nine hips (144 patients) with hip dysplasia (52 F:107 M) out of 1893 patients with hip pain were included. Of these, 45 (28%) had severe hip dysplasia with a lateral center-edge angle ≤18°. Mean age at time of presentation was 26.1 (±10.1) years. Mean follow-up time was 8.2 (±5) years. The rate of OA was 20%. THA was performed in 11% of patients. Body mass index >29 (P = 0.03) and increased age (P < 0.01) were risk factors for OA. Patients with symptomatic hip dysplasia are at significant risk of developing hip OA. Body mass index >29 and age ≥35 years at the time of presentation with hip pain were risk factors for hip OA.

The Impact of Pain on Functionality, Postural Control and Fall Risk in Woman Aged 45 to 64 Years Old

BACKGROUND

Ageing in women is associated with chronic degenerative pain leading to a functional decrease and therefore increase fall risk. It is therefore essential to detect early functional decreases in the presence of pain related to osteoarthritis.

OBJECTIVE

This cross-sectional study aimed to assess the impact of pain on functionality, postural control and fall risk in women aged between 45 to 64 years old.

METHODS

Twenty-one (21) women aged 45 to 64 were evaluated by clinical and functional measures such as a pain questionnaire (Lequesne Index), functional tests (Stair Step Test, 5 times sit-to-stand, 6MWD, Timed-up and Go) and postural performance (under force platform). Women were classified into 2 groups from the Lequesne Pain Index (PI): low pain (score ≤ 9) and strong pain (score ≥ 10) for subsequent comparisons on functionality (physical and postural control performance).

RESULTS

A significant impact was observed between the pain index (strong PI) and 3 of the 4 functional tests carried out including Stair Step Test (p = 0.001; g = 1.44), walking distance (p = 0.003; g = 1.31) and Timed-up and Go (p = 0.04; g = -0.93). The group with a strong PI score reported further poor postural control under force platform compared to the weak pain group.

CONCLUSION

Pain and severity based on the PI index negatively modulate physical and postural control performance in women aged 45 to 64 years old.

Using multivariable Mendelian randomization to estimate the causal effect of bone mineral density on osteoarthritis risk, independently of body mass index

OBJECTIVES

Observational analyses suggest that high bone mineral density (BMD) is a risk factor for osteoarthritis (OA); it is unclear whether this represents a causal effect or shared aetiology and whether these relationships are body mass index (BMI)-independent. We performed bidirectional Mendelian randomization (MR) to uncover the causal pathways between BMD, BMI and OA.

METHODS

One-sample (1S)MR estimates were generated by two-stage least-squares regression. Unweighted allele scores instrumented each exposure. Two-sample (2S)MR estimates were generated using inverse-variance weighted random-effects meta-analysis. Multivariable MR (MVMR), including BMD and BMI instruments in the same model, determined the BMI-independent causal pathway from BMD to OA. Latent causal variable (LCV) analysis, using weight-adjusted femoral neck (FN)-BMD and hip/knee OA summary statistics, determined whether genetic correlation explained the causal effect of BMD on OA.

RESULTS

1SMR provided strong evidence for a causal effect of BMD estimated from heel ultrasound (eBMD) on hip and knee OA {odds ratio [OR]hip = 1.28 [95% confidence interval (CI) = 1.05, 1.57], p = 0.02, ORknee = 1.40 [95% CI = 1.20, 1.63], p = 3 × 10-5, OR per standard deviation [SD] increase}. 2SMR effect sizes were consistent in direction. Results suggested that the causal pathways between eBMD and OA were bidirectional (βhip = 1.10 [95% CI = 0.36, 1.84], p = 0.003, βknee = 4.16 [95% CI = 2.74, 5.57], p = 8 × 10-9, β = SD increase per doubling in risk). MVMR identified a BMI-independent causal pathway between eBMD and hip/knee OA. LCV suggested that genetic correlation (i.e. shared genetic aetiology) did not fully explain the causal effects of BMD on hip/knee OA.

CONCLUSIONS

These results provide evidence for a BMI-independent causal effect of eBMD on OA. Despite evidence of bidirectional effects, the effect of BMD on OA did not appear to be fully explained by shared genetic aetiology, suggesting a direct action of bone on joint deterioration.