An update on the science and therapy of obesity and its relationship to osteoarthritis

A robust NIR fluorescence-activated probe for peroxynitrite imaging in cells and mice osteoarthritis models

Osteoarthritis (OA) is the most common type of joint disease, which is difficult to treat, but early standardized diagnosis and treatment can effectively alleviate the pain and symptoms of patients. Therefore, it is important to construct an effective tool to assist in the early diagnosis and evaluation of the therapeutic effect of OA. In this work, a near-infrared (NIR) fluorescence-activated fluorescent probe, YB-1, was constructed for the evaluation of the diagnostic and therapeutic efficacy of OA via detection and imaging of the biomarker of ONOO- in inflammatory cells and mice osteoarthritis models. YB-1 exhibited high selectivity, high sensitivity, and a high ratio yield (I668/I0) fluorescence increasing (∼30 folds). Besides, YB-1 can be used effectively to image endogenous and exogenous ONOO- in living human chondrocytes cells (TC28a2), as well as to evaluate the effect of drug (Chrysosplenol D, CD) treatment in IL-1β-induced inflammatory cells model. Interestingly, YB-1 was available for OONO- imaging analysis in the collagenase-induced mice OA models and assessment of the effect of CD treatment in mice OA models, with good results. Thus, the newly constructed YB-1 is a powerful molecular tool for the diagnosis and treatment of OA-related diseases.

Comparison of weight bearing functional exercise and non-weight bearing quadriceps strengthening exercise on pain and function for people with knee osteoarthritis and obesity: protocol for the TARGET randomised controlled trial

Background

Clinical guidelines recommend exercise as a core treatment for individuals with knee osteoarthritis (OA). However, the best type of exercise for clinical benefits is not clear, particularly in different OA subgroups. Obesity is a common co-morbidity in people with knee OA. There is some evidence suggesting that non-weight bearing exercise may be more effective than weight bearing exercise in patients with medial knee OA and obesity.

Methods

To compare the efficacy of two different exercise programs (weight bearing functional exercise and non-weight bearing quadriceps strengthening) on pain and physical function for people ≥50 years with painful medial knee OA and obesity (body mass index ≥30 kg/m²) 128 people in Melbourne, Australia will be recruited for a two group parallel-design, assessor- and participant-blinded randomised controlled trial. Participants will be randomly allocated to undertake a program of either weight bearing functional exercise or non-weight bearing quadriceps strengthening exercise. Both groups will attend five individual sessions with a physiotherapist who will teach, monitor and progress the exercise program. Participants will be asked to perform the exercises at home four times per week for 12 weeks. Outcomes will be measured at baseline and 12 weeks. Primary outcomes are self-reported knee pain and physical function. Secondary outcomes include other measures of knee pain, physical function, quality-of-life, participant-perceived global change, physical performance, and lower limb muscle strength.

Discussion

This study will compare the efficacy of two different 12-week physiotherapist-prescribed, home-based exercise programs for people with medial knee OA and obesity. Findings will provide valuable information to help inform exercise prescription in this common OA patient subgroup.

Trial registration

Australian New Zealand Clinical Trials Registry reference: ACTRN12617001013358, 14/7/2017

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2662-5) contains supplementary material, which is available to authorized users.

Efficacy and Treatment Response of Intra-articular Corticosteroid Injections in Patients With Symptomatic Knee Osteoarthritis

INTRODUCTION

Intra-articular corticosteroid injections are often used for short-term pain relief in patients with knee osteoarthritis (OA). This study investigates the efficacy of intra-articular corticosteroid injections in patients with symptomatic knee OA and factors that affect treatment response.

METHODS

This prospective, multicentered cohort study had 100 participants with radiographic evidence of knee OA enrolled. Participants received one corticosteroid injection into the affected knee and were evaluated before the injection (baseline) and at 3 weeks, 6 weeks, 3 months, and 6 months after the injection.

RESULTS

Participants' Visual Numeric Scale and Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores improved at all time points except for the Visual Numeric Scale score at 6 months, compared with baseline scores (P < 0.001). Participants with Kellgren-Lawrence grade 1 or 2 OA saw clinical improvement in the WOMAC scores at all time points, compared with the baseline score (P < 0.01). Compared with all other subgroups, obese patients with Kellgren-Lawrence grade 3 or 4 OA had significantly worse WOMAC scores at baseline, 6 weeks, and 3 months (P < 0.01 and P < 0.01, respectively).

DISCUSSION

Our findings validate previously established guidelines for nonsurgical management of knee OA and suggest that intra-articular corticosteroid injections may be an acceptable short-term management option in patients unwilling or unable to undergo surgical treatment. Obesity and OA severity affect the efficacy of intra-articular corticosteroid injections.

CONCLUSION

Patients receiving intra-articular corticosteroid injections had improved pain and function. Clinicians should expect less improvement in patients with obesity and/or advanced arthritis. Clinical benefits of intra-articular injections in these patients are less predictable.

Obese patients may have more soft tissue impingement following primary total hip arthroplasty

PURPOSE

Several studies have reported a risk of dislocation in obese patients after total hip arthroplasty. In this study, we evaluated the interaction between obesity and dislocation by kinematic analysis using a navigation system.

METHODS

The intraoperative range of motion (ROM) and postoperative impingement-free ROM were measured in 38 patients, and we compared the impingement-free ROM in obese and non obese patients.

RESULTS

The postoperatively simulated ROM was similar in the obese and non obese groups. The intraoperative ROM was smaller in the obese group. The difference values between the intraoperative ROM and postoperatively simulated ROM were larger in the obese group. These results indicate that obese patients have less ROM following primary total hip arthroplasty even when the implant positioning is performed correctly.

CONCLUSIONS

Dislocations are multifactorial problems including soft tissue impingement. Therefore, the risk of dislocation caused by soft tissue impingement in obese patients may be increased.

Two-year outcomes in primary THA in obese male veterans administration medical center patients

The objective of this study was to examine the influence of obesity on the rate of infection, dislocation, and overall complications in a group of male patients undergoing primary total hip arthroplasty (THA). The study involved a retrospective review of the association of body mass index (BMI) and dislocation, infection, and complications on 255 consecutive male patients who received a THA. BMI of 40 and greater had significantly more dislocations and approached significance for infections. The present study suggests that the risk of infection and dislocation increases only in highly obese males (BMI > 40) in contrast to other studies that have reported a higher risk infection, dislocation, and complications with a BMI of obesity in females (BMI > 30).

Moderately overweight and obese patients in general practice: a population based survey

Background

Obesity is a main threat to public health in the Western world and is associated with diseases such as diabetes mellitus and coronary heart diseases. Up to now a minority of research studied the relation between obesity and the use of primary health care. In the Netherlands the general practitioner (GP) is the main primary health care provider. The objective of this article is to evaluate GP consultation and prescription of drugs in moderate and severely overweight (obese) persons in the Netherlands.

Methods

Data were used from a representative survey of morbidity in Dutch general practice in 2001. Our study sample consisted of 8,944 adult respondents (18+ years) who participated in an extensive health interview. Interview data were linked to morbidity and prescription registration data from 95 general practices where respondents were listed. Body mass index (BMI) was calculated using self-reported height and weight. Analyses were controlled for clustering within practices as well as for socio-demographic and life style characteristics.

Results

Obesity (BMI ≥ 30 kg/m2) was observed in 8.9% of men and 12.4% of women; for moderate overweight (BMI 25-<30 kg/m2) these percentages were 42.2% and 30.4% respectively. Obese men and women were more likely to consult their GP than persons without overweight. This especially holds for diseases of the endocrine system, the cardiovascular system, the musculoskeletal system, the gastro-intestinal system, and skin problems. Related to this, obese men and women were more likely to receive drugs for the cardiovascular system, the musculoskeletal system, alimentary tract and metabolism (including, for example, antidiabetics), and dermatologicals, but also antibiotics and drugs for the respiratory system. For moderately overweight men and women (BMI 25-<30 kg/m2) smaller but significant differences were found for diseases of the endocrine system, the cardiovascular system, and the musculoskeletal system.

Conclusion

Obesity increases the workload of Dutch general practitioners and the use of prescribed medication. The current increase in the prevalence of obesity will further increase the use of health care and related costs. Since a large majority of Dutch persons visit their GP over the course of one year, GPs' potential role in effective prevention strategies cannot be denied.

Does Knee Osteoarthritis Alter the Neuromuscular Responses to a Perturbation During Single Lower Limb Stance?

PURPOSE

Evidence substantiating an association between knee osteoarthritis (OA) and altered joint protection responses is relevant to the management of knee OA. The purpose of this study was to detect neuromuscular response times of the vastus lateralis and biceps femoris muscles following a perturbation during single lower limb stance. We hypothesized that muscle response times are: (1) delayed in older adults with knee OA when compared to young and older adults (without diagnosed knee OA) and (2) dependent on the magnitude of load released.

SUBJECTS

Ten young adults, 10 older adults, and 7 older adults with symptomatic knee OA participated.

METHODS

While in single lower limb stance, the subjects flexed the knee into a range of 33 to 37 degrees while a posterior load of either 6 or 9 kg was applied at the proximal tibia. The load was released after the subjects held the required position for 1 full second. Muscle response times were measured by electromyography. Separate 3 (group) by 2 (load) mixed factorial analysis of variance procedures were performed for electromyography data from the vastus lateralis and biceps femoris.

RESULTS

There was no difference in vastus lateralis response times between older adults with knee OA and older adults or between older adults with knee OA and young adults. Older adults did have longer vastus lateralis response times than young adults. There was no difference in biceps femoris response times between older adults with knee OA and older adults; however, both groups had longer biceps femoris response times than young adults. Furthermore, there were no differences in either vastus lateralis or biceps femoris response times between 6 kg and 9 kg loads.

CONCLUSION

Although knee OA did not alter muscle responses in our study, the type of functional weightbearing perturbation described could be safely used in the physical therapy clinic to help improve balance and stability while decreasing discomfort in older adults with symptomatic knee OA.

Welchen Einfluss hat Übergewicht auf die Ergebnisse von Hüft- und Knieendoprothesen

As the prevalence of obesity worldwide continues to rise, defining the relationship between obesity and arthroplasty outcomes becomes increasingly important. The effect of obesity on the outcome of total hip or knee arthroplasty has been reported to be variable. Some authors believe that a high body weight will lead to less than optimal arthroplasty outcomes, because increased body weight leads to increased stress across the components and an increased load on the surrounding bone. Although this should, in turn, lead to a higher incidence of aseptic loosening or prosthetic failure in obese patients, studies have suggested that the effect of increased body weight and arthroplasty outcome are not so straightforward. The lower activity level typically observed in obese patients may partially counter the negative effects of increased weight on the bone-prosthesis interface. Although results do not show significant differences in all studies, it appears that obesity has negative impact on the results of total hip and knee arthroplasty. Therefore, long-term studies using large sample sizes should be conducted. If significant differences are demonstrated, an altered course of treatment, such as having a patient lose weight before considering a total hip or knee arthroplasty, might be advocated.

Impact of demographic and impairment-related variables on disability associated with plantar fasciitis

BACKGROUND

Plantar fasciitis is a common foot disorder that impacts many functional activities. Research that quantifies the impact that plantar fasciitis has on function is lacking. In addition, little is known about which variables are associated with disability in patients with plantar fasciitis. The first purpose of this study was to determine if age, gender, body mass index, pain intensity, chronicity of symptoms, or ankle dorsiflexion range of motion was associated with disability in patients with plantar fasciitis. The second purpose was to describe the impact that plantar fasciitis has on functional status in the context of five functional domains: household activities of daily living, usual work and hobbies, nonweightbearing activities, walking-related activities, and running-related activities.

METHODS

Fifty consecutive patients diagnosed with unilateral plantar fasciitis were recruited. Demographic and impairment data were collected and all patients completed the Lower Extremity Functional Scale (LEFS), a validated self-report measure of disability. Multiple regression analysis was used to describe the association between the variables and disability. Graphs depicting five domains of function derived from the LEFS were generated to describe the extent of disability.

RESULTS

Body mass index (BMI) was the only variable that was significantly associated with disability (F = 9.87, p =.003). Measures of pain intensity, ankle dorsiflexion, age, gender, chronicity, and time spent weightbearing were not related to disability. Plantar fasciitis showed distinct patterns of disability depending on the functional domain that was assessed.

CONCLUSIONS

With the exception of BMI, impairment and demographic variables do not predict the extent of functional loss in patients with plantar fasciitis. The most likely domains of function to be at least moderately affected in patients with plantar fasciitis are running-related activities and usual work or hobbies.

Obesity is not associated with increased knee joint torque and power during level walking

While it is widely speculated that obesity causes increased loads on the knee leading to joint degeneration, this concept is untested. The purpose of the study was to identify the effects of obesity on lower extremity joint kinetics and energetics during walking. Twenty-one obese adults were tested at self-selected (1.29m/s) and standard speeds (1.50m/s) and 18 lean adults were tested at the standard speed. Motion analysis and force platform data were combined to calculate joint torques and powers during the stance phase of walking. Obese participants were more erect with 12% less knee flexion and 11% more ankle plantarflexion in self-selected compared to standard speeds (both p<0.02). Obese participants were still more erect than lean adults with approximately 6 degrees more extension at all joints (p<0.05, for each joint) at the standard speed. Knee and ankle torques were 17% and 11% higher (p<0.034 and p<0.041) and negative knee work and positive ankle work were 68% and 11% higher (p<0.000 and p<0.048) in obese participants at the standard speed compared to the slower speed. Joint torques and powers were statistically identical at the hip and knee but were 88% and 61% higher (both p<0.000) at the ankle in obese compared to lean participants at the standard speed. Obese participants used altered gait biomechanics and despite their greater weight, they had less knee torque and power at their self-selected walking speed and equal knee torque and power while walking at the same speed as lean individuals. We propose that the ability to reorganize neuromuscular function during gait may enable some obese individuals to maintain skeletal health of the knee joint and this ability may also be a more accurate risk indicator for knee osteoarthritis than body weight.

A low-fat intake and greater activity level are associated with lower weight regain 3 years after completing a very-low-calorie diet

OBJECTIVE

To examine the roles of diet, exercise, and lifestyle factors in determining long-term weight regain after weight loss with a very-low-calorie diet (VLCD).

SUBJECTS

Twenty-seven of 38 women who lost weight with a VLCD.

DESIGN

Graduates of a weight loss intervention study returned for follow-up 3 years after program completion. Percentage of initial weight loss that was regained was correlated with subjects' fat intake (assessed via 7-day food records and a Diet Habit Survey), energy intake (assessed via 7-day food records), activity level and lifestyle factors (assessed via questionnaires) that are supportive of weight loss maintenance.

STATISTICAL ANALYSES PERFORMED

Regression analysis was used to assess the relationship of weight regain with fat intake, activity level, and energy intake. Contingency table analysis was used to assess the association between weight regain and lifestyle factors.

RESULTS

Subjects followed experienced a -20.7kg+/-9.2kg (-19.2%+/-7%) (mean+/-standard deviation) weight change during the original VLCD program and a 13.9kg+/-11.3kg (76.6%+/-52.1%) weight change 3 years post-VLCD. Fat intake, assessed by a 7-day food diary, was positively correlated with weight regain at 3 years (r=0.66, P=.0004). Less weight regain was also seen with a lower percent fat intake as reflected by a higher Diet Habit Survey score (r=-0.55, P=.004). Women with the lowest tertile of reported fat intake (<25% of energy) from the Diet Habit Survey regained the least amount of weight (P=.05). Activity level was negatively correlated with weight regain (r=-0.53, P=.005). After correction for multiple comparisons, there was no association between total energy intake and weight regain. Lifestyle factors were also not associated with weight regain.

APPLICATIONS/CONCLUSIONS

Identifying strategies to maintain weight loss is crucial because of the negative health effects and increasing prevalence of obesity. For women who have lost weight on a VLCD, limiting dietary fat intake and maintaining physical activity are both important factors for the prevention of weight regain. To promote better weight loss outcomes, registered dietitians should help clients who have lost weight limit their fat intake to less than 30% of energy and encourage high activity levels.