Improvements in Health-Related Quality of Life and Pain: A Cohort Study in Obese Patients After Laparoscopic Sleeve Gastrectomy

Abstract

Objective:

The principal aim of the study was to investigate the effect of the sleeve gastrectomy (SG) in the quality of life (QoL) and pain in a population of morbidly obese patients.

Methods:

Seventy-two SG patients were assessed in this descriptive observational study, before the surgery and 6 months after that. We evaluated health-related QoL (Gastrointestinal Quality of Life Index [GIQLI]) and pain (spontaneous low back pain by Numerical Point Rate Scale [NPRS] and pressure pain thresholds [PPTs]).

Results:

The results of the analysis of variance (ANOVA) revealed significant improvements in nearly all of the subscales of GIQLI questionnaire after 6 months: gastrointestinal symptoms (P = .01), physical well-being (P < .001), social well-being (P = .03), and total GIQLI score (P < .001), but not for the emotional condition (P = .20). Patients also had improvements in spontaneous low back pain (P = .002), but not in the PPTs in all the body areas explored, including the cervical area, low back, and hands (P > .05).

Conclusion:

Patients receiving SG improved their health-related QoL and low back pain 6 months after the intervention, but this improvement was not so important for pressure pain thresholds in different body areas.

Introduction

The prevalence of morbid obesity is increasing around the world¹ and the effectiveness of surgical treatment has led to the development of new procedures to lose weight with the least morbidity possible. Sleeve gastrectomy (SG) is a restrictive procedure, consisting of vertical gastrectomy, including the entire greater curvature of the stomach.² Its principal benefits are a low rate of complications, absence of malabsorption, and maintenance of gastrointestinal continuity.^3,4

In addition to an increased risk of morbidity and mortality, obesity is often associated with psychosocial disabilities and poor quality of life (QoL).^5,6 Weight loss achieved by the surgical procedure may improve life expectancy⁷ and health-related QoL.^8,9 Specifically, SG has demonstrated effectiveness in reducing comorbidities, such as diabetes, hypertension, hyperlipidemia, sleep apnea, and so on.^10–13 In fact, the ultimate goal of bariatric surgery is weight loss and the decrease of these obesity-related comorbidities to improve the QoL of morbidly obese patients. QoL is a subjective parameter determined by the patients. Previous research has investigated the improvement in the QoL in morbidly obese patients who underwent different bariatric procedures,^14,15 and different instruments have been developed for the assessment of QoL, both general and bariatric specific in nature. However, the information available about the improvement achieved by the SG is still scarce, but some previous work comparing SG and laparoscopic adjustable gastric band (LAGB) stated that postoperative QoL is better in the SG group of patients¹⁶ and may be related to the comorbidities resulting from the LAGB procedure and the faster weight loss achieved after SG.

Moreover, it is known that obesity can contribute to pain and physical impairments, such as decreased cardiorespiratory function, inflammation, low strength, reduced flexibility, depression, and so on.^17–20 A previous meta-analysis has suggested that the strongest association is between overweight and obesity and seeking care for low back pain and chronic low back pain.²¹

As bariatric surgery leads to weight reduction, it is expected that this weight loss may reduce these pain and physical limitations. Some research had investigated the positive effect of bariatric surgery on back pain symptoms.^22–25 This research assessed pain through questionnaires that only evaluate the subjective factor of pain. It would be helpful to evaluate the objective aspect of back pain in morbidly obese patients before and after surgery. In fact, a recent study has stated that obese people are less sensitive than nonobese individuals, but only in areas with excess subcutaneous fat,²⁵ but we do not know how the loss of fat could determine a possible loss of sensitivity. Nevertheless, a subsequent review stated that the relationship between obesity and pain sensitivity is not likely to be linear and the exact nature of this relationship is not known.²⁶

Our hypothesis was that patients undergoing an obesity surgery by SG experienced an important improvement in health-related QoL and in pain processes in general within 6 months after the surgical procedure.

The aim of current study was to investigate the effect of the SG in the health-related QoL and pain processes in a population of morbidly obese patients.

Methods

A descriptive observational study with a 6-month follow-up was performed in 72 patients operated through laparoscopic SG in the General Surgery Service of San Cecilio Universitary Hospital in Granada (Spain). The inclusion criteria were: (1) adults at least 18 years, (2) morbid obesity with indications for surgical treatment (body mass index [BMI] >35 with comorbidities or BMI >40 m/kg²), and (3) had signed informed consent. The exclusion criteria were: (1) patients with general anesthesia contraindication, (2) pregnancy, (3) previous bariatric, gastric surgery, or cholecystectomy, (4) uncontrolled medical diseases, (5) uncontrolled psychiatric conditions, and (6) ventral or hiatal hernia.

Ninety patients were recruited to participate in the study. Finally, 72 met the inclusion criteria, accepted their addition to the study, signed the informed consent following the Helsinki Declaration, and finalized the study process. The study was approved by the Biohealth Ethics Committee of the Province of Granada (Spain). A member of the surgical team informed the patients about the study characteristics. Sociodemographic and clinical characteristics were obtained by an ad hoc questionnaire and clinical records from the hospital.

Patients were assessed a few days before the surgical treatment (preintervention) and postintervention at 1 and 6 months. The patients were asked to avoid analgesics or muscle relaxants for 24 hours before the evaluation.

Instruments

Gastrointestinal Quality of Life Index

The Gastrointestinal Quality of Life Index (GIQLI) questionnaire was designed by Eypasch et al.²⁷ to assess health-related QoL in patients with gastrointestinal disease. This instrument measures four domains: gastrointestinal symptoms (19 questions), physical function (7 questions), emotional function (5 questions), and social function (5 questions) in 36 total questions. Each question can be scored from 0 to 4 (0 being the worst and 4 the best option). The maximum possible score is 144 (the higher score, the higher QoL). A previous study supports the validity and reliability of the Spanish version.²⁸

Numerical Point Rate Scale

We used an 11-point Numerical Point Rate Scale (NPRS)²⁹ (0 = no pain, 10 = maximum pain) to assess the intensity of spontaneous low back pain.

Pressure pain thresholds

Pressure pain threshold (PPT) is the minimal amount of pressure where the sensation changes to pain.³⁰ We used a digital algometer (Somedic AB, Farsta, Sweden) to assess the PPT levels in our sample. The pressure applied was at a rate of 30 kPa/s approximately, by a probe of 1 cm². The patients were lying in a supine or prone position and they had to press the switch when the sensation changed from pressure to pain. We calculated the mean of three trials on each point. This assessment method has been shown to have a high reliability (intraclass correlation coefficient = 0.91 [95% confidence interval 0.82–0.97]).³¹

The PPTs were assessed bilaterally over the low back (at the height of the fifth lumbar vertebrae spinous process and placing the algometer in the paraspinal area in the middle of the erector spinae muscle belly),³² the C5-C6 zygapophyseal joint, and the second metacarpal, as a distant point.³³

Statistical analysis

The descriptive data are described as mean ± SD for the continuous variables and absolute frequency for the categorical variables. We used the Kolmogorov–Smirnov test to test the normal distribution of the variables. An analysis of variance (ANOVA) was performed, using time as an intersubject factor (preintervention and 1 and 6 months after intervention). A post hoc analysis with multiple comparisons was developed using the Bonferroni test. The statistical analysis was conducted at a 95% confidence level, and a P value less than .05 was considered as statistically significant. This statistical analysis was performed using the SPSS statistical software, version 22.0 (SPSS, Inc., Chicago, IL).

Results

Seventy-two patients aged 45.36 ± 9.38 years who had undergone SG participated in the study. Twenty-five (34.7%) were men and 47 (65.3%) were women. Forty-four (61.1%) morbidly obese patients were married, 17 (23.6%) were unmarried, 4 (5.6%) were divorced, and 7 (9.7%) were widowed at the time of the study. Twenty (27.8%) patients were smokers, whereas 51 (70.8%) were nonsmokers and 1 (1.4%) was an ex-smoker. Finally, comorbidities at the beginning of the study and its resolution after the follow-up period are presented in Table 1.

Table 1.

Comorbidities and Its Known Resolution After the Follow-Up Period

Variable n = 72	Comorbidities	Resolution after 6 months
Weight (kg)	130.67 ± 21.34	25.77% TWL
Hypertension	68 (94%)	26.2%
Insulin-dependent diabetes mellitus	14 (19%)	10%
Noninsulin-dependent diabetes mellitus	51 (70.83%)	—
Obstructive sleep apnea syndrome	57 (79.16%)	—
Anxiety depression	26 (36.11%)	—
Arthrosis-osteoporosis	19 (26.38%)	—

Values are expressed as mean ± SD and absolute percentages.

TWL, total weight loss.

Gastrointestinal Quality of Life Index

The results of the ANOVA showed a statistically significant effect of the surgery on the majority of the scales in the GIQLI questionnaire, specifically, in gastrointestinal symptoms (F = 4.05; P = .01). In the post hoc analysis, there were no better results between the preintervention time and 1 month (P = .10) and between preintervention and the 6 months (P = 1), but a significant improvement between the assessments at 1 and 6 months (P = .02) was observed. In physical well-being, there were also statistically significant effects of the surgery after 6 months (F = 32.29; P < .001). In the post hoc analysis there were differences between preintervention and 1 month (P < .001) and preintervention and 6 months (P < .001), but not between 1 and 6 months assessments (P = .23). In social well-being, there were differences between the times of the study (F = 3.44; P = .03). The post hoc analysis showed differences between preintervention time and 6 months (P = .03), but not between preintervention and 1 month (P = .27) and 1 and 6 months (P = 1.00). Finally, in the total GIQLI score there were also statistically significant differences (F = 9.26; P < .001).The post hoc analysis showed differences in preintervention and 6 months (P < .001) and 1 and 6 months (P = .05), but not between preintervention and 1 month (P = .16).

Finally, in the emotional condition, there were no statistically significant differences between the times of the study (F = 1.60; P = .20).

Low back pain (NPRS)

The analysis revealed a statistically significant effect of the SG on the pain perception in the low back (F = 6.17; P = .001). The post hoc analysis showed general differences between preintervention time and 6 months (P = .001), but not between preintervention and 1 month (P = .43) and from 1 to 6 months (P = .13).

Pressure pain thresholds

Finally, the statistical analysis revealed no significant changes in PPTs after the intervention in our sample of morbidly obese patients in the right C5-C6 zygapophyseal joint (F = 0.92; P = .39), left C5-C6 zygapophyseal joint (F = 1.71; P = .18), right low back (F = 0.47; P = .62), left low back (F = .39; P = .67), right second metacarpal (F = 0.19; P = .82), and left second metacarpal (F = 0.24; P = .78).

Table 2 summarizes the descriptive data of patients across all the study variables before the surgery and at 1 and 6 months postsurgery.

Table 2.

Descriptive Data of Patients Before the Surgery and at 1 and 6 Months of Follow-Up

	Preintervention	1 month postintervention	6 months postintervention	P value
Digestive symptoms	51.65 ± 10.22	48.11 ± 9.85	52.66 ± 9.89	.019^*
Emotional condition	12.47 ± 4.86	13.25 ± 3.10	13.57 ± 3.14	.204
Physical function	9.73 ± 5.10	15.80 ± 6.84	17.56 ± 6.28	.000^**
Social function	10.98 ± 3.84	12.05 ± 3.55	12.61 ± 3.94	.034^*
Total GIQLI score (0–144)	83.58 ± 15.69	88.95 ± 17.63	95.66 ± 16.69	.000^**
Low back pain (NPRS)	3.95 ± 3.73	3.12 ± 3.43	1.97 ± 2.95	.002^**
PPT right C5-C6 zygapophyseal joint	357.56 ± 211.25	378.40 ± 237.16	406.98 ± 203.60	.397
PPT left C5-C6 zygapophyseal joint	353.79 ± 205.75	374.73 ± 241.57	404.94 ± 184.77	.351
PPT right low back	428.36 ± 239.43	436.89 ± 275.80	466.65 ± 220.06	.622
PPT left low back	420.64 ± 230.41	437.26 ± 281.53	456.82 ± 218.02	.677
PPT right second metacarpal	470.09 ± 236.74	447.83 ± 230.62	463.32 ± 182.71	.823
PPT left second metacarpal	457.40 ± 226.30	437.26 ± 239.33	460.92 ± 181.01	.782

Values are expressed as mean ± SD (95% confidence interval).

Significant differences between times of study (ANOVA test) ^*P < .05; ^**P < .01.

ANOVA, analysis of variance; GIQLI, Gastrointestinal Quality of Life Index; NPRS, Numerical Point Rate Scale; PPT, pressure pain threshold.

Discussion

The principal aim of the current study was to determine the effect of SG on QoL and pain in morbidly obese patients. The results show a significant general improvement in auto-informed health-related QoL and spontaneous lumbar pain in morbidly obese patients after 6 months of follow-up. Nevertheless, there were no significant improvements in sensitization, studied through pressure pain thresholds.

The study revealed an impaired QoL in morbidly obese people. Our results are 30% lower than those reported in a healthy population with similar characteristics³⁴ and they are in agreement with previously reported results of the GIQLI questionnaire in morbidly obese people.^34,35 These results were significantly better after 6 months from the SG, which is consistent with previous works assessing QoL after treatment with SG,^15,34,35 demonstrating that SG is an effective procedure that leads to positive changes in health-related QoL, as well as weight reduction. In the majority of domains of GIQLI changes occurred between the preintervention time and 6 months follow-up, but in the symptoms domain, patients suffered deterioration at 1 month, possibly due to the typical discomfort of the first days after the laparoscopic surgery procedure.

Another finding of our study was the improvement in spontaneous low back pain after the surgical procedure. Our patients presented with nearly 40% more spontaneous pain than healthy adults of a similar age, before the surgical operation,^32–37 but our results do not completely agree with those reported by Khoueir et al.²² where low back pain was more than 1 point higher than the same pain in our sample of patients before the surgery and 2 points lower in the group of patients studied by Melissas et al.³⁸ Moreover, several studies have shown a positive relationship between excess body weight and back diseases,^38–40 although other works have failed to probe this positive association.^41,42 Nevertheless, in the current research, the reduction in low back pain 6 months after the intervention reaches almost 50% and it is in line with the work of Khoueir et al.,²² who found a reduction of 44% after 6 months of bariatric surgery in 58 patients with morbid obesity; and another similar study³⁸ concluded that low back pain assessed with the Visual Analog Scale significantly improved in 29 morbidly obese patients 2 years after bariatric surgery.

Concerning the PPTs, our study revealed similar values to healthy subjects with similar characteristics in low back area³² and 40% lower scores in the cervical area⁴³; these findings are not consistent with a previous study²⁵ revealing that obese patients are less sensitive for painful stimuli compared with nonobese individuals, suggesting that this effect is mediated by the excess of subcutaneous fat. Surprisingly, PPTs showed general improvements after SG in our sample of patients in the spine area, although these changes were not statistically significant. Perhaps the follow-up time was too short to reveal significant improvement in a condition that patients had suffered for many years and longer time is necessary to decrease the influence of this pain input in the central nervous system of patients. Moreover, the role that the muscle mass plays in musculoskeletal pain is known,⁴⁴ and as our study did not control the physical activity of the patients, future works may need to investigate the impact of developing muscle mass within the weight loss on this type of pain. In addition, a comparison between obese patients waiting for a surgical operation and a control group may be interesting to determine the influence of body fat in pain sensitivity.

Finally, some limitations of the study must be stated. The current work examined 72 nonrandomized or controlled patients and with a follow-up of 6 months; so future research is needed to improve the results and the generalization of them. Besides this, factors that might influence the observed improvements, including lifestyle changes produced by hospital recommendations on diet control and especially increased physical activity after SG, were not included in this study. Nevertheless, to the best of our knowledge, this is one of the first studies to analyze the influence of SG on QoL and pain in a cohort of obese patients.

Conclusion

Patients with morbid obesity operated by laparoscopic SG improved their health-related QoL and reported low back pain 6 months after the intervention, but this improvement was not so important in pressure pain thresholds in different body areas.

Footnotes

Acknowledgments

The authors are grateful to all patients who accepted to participate in this study.

Disclosure Statement

No competing financial interests exist.

References

World Health Organization. Global Health Observatory (GHO) data. Obesity. Situation and trends; 2016. Available at: www.who.int/gho/ncd/risk_factors/obesity_text/en/ (last accessed January 1, 2017).

Chivot

, Robert

, Lafaye

, et al. Laparoscopic sleeve gastrectomy: Imaging of normal anatomic features and postoperative gastrointestinal complications. Diagn Interv Imaging, 2013; 94:823–834.

Fuks

, Verhaeghe

, Brehant

, et al. Results of laparoscopic sleeve gastrectomy: A prospective study in 135 patients with morbid obesity. Surgery, 2009; 145:106–113.

Torgersen

, Osmolak

, Forse

. Sleeve gastrectomy and Roux En Y gastric bypass: Current state of metabolic surgery. Curr Opin Endocrinol Diabetes Obes, 2014; 21:352–357.

Favricatore

, Wadden

, Sarwer

, Faith

. Health-related quality of life and symptoms of depression in extremely obese persons seeking bariatric surgery. Obes Surg, 2005; 15:304–309.

Sarwer

, Wadden

, Fabricatore

. Psychosocial and behavioral aspects of bariatric surgery. Obes Res, 2005; 13:639–648.

Bray

. The missing link-lose weight, live longer. N Engl J Med, 2007; 23:818–820.

Larsen

, Geenen

, van Ramhorst

, et al. Psychosocial functioning before and after laparoscopic adjustable gastric banding: A crosssectional study. Obes Surg, 2003; 13:629–636.

Dymek

, Le Grange

, Neven

, Alverdy

. Quality of life and psychosocial adjustment in patients after Roux-en-Y gastric bypass: A brief report. Obes Surg, 2001; 11:32–39.

10.

Hamoui

, Anthone

, Kaufman

, Crookes

. Sleeve gastrectomy in the high-risk patient. Obes Surg, 2006; 16:1445–1449.

11.

Silecchia

, Boru

, Pecchia

, et al. Effectiveness of laparoscopic sleeve gastrectomy (first stage of biliopancreatic diversion with duodenal switch) on co-morbidities in super-obese high risk patients. Obes Surg, 2006; 16:1138–1144.

12.

Charalampakis

, Bertsias

, Lamprou

, de Bree

, Romanos

, Melissas

. Quality of life before and after laparoscopic sleeve gastrectomy. A prospective cohort study. Surg Obes Relat Dis, 2015; 11:70–76.

13.

Desiderio

, Trastulli

, Scalercio

, Carloni

, Cirocchi

, Boselli

, Noya

, Parisi

. Metabolic surgery for the treatment of type 2 diabetes mellitus: Safety and feasibility of laparoscopic sleeve gastrectomy. J Laparoendosc Adv Surg Tech Part B Videoscop, 2013.

14.

Chevallier

, Zinzindohoue

, Douard

, et al. Complications after laparoscopic adjustable gastric banding for morbid obesity: Experience with 1,000 patients over 7 years. Obes Surg, 2004; 14:407–414.

15.

Spivak

, Hewitt

, Onn

, Half

. Weight loss and improvement of obesity-related illness in 500 U.S. patients following laparoscopic adjustable gastric banding procedure. Am J Surg, 2005; 189:27–32.

16.

Alley

, Fenton

, Harnisch

, Tapper

, Pfluke

, Peterson

. Quality of life after sleeve gastrectomy and adjustable gastric banding. Surg Obes Relat Dis, 2012; 8:31–40.

17.

Hulens

, Vansant

, Lysens

, Claessens

, Muls

. Exercise capacity in lean versus obese women. Scand J Med Sci Sports, 2001; 11:305–309.

18.

Vincent

, Heywood

, Connelly

, Hurley

. Obesity and weight loss in the treatment and prevention of osteoarthritis. PM R, 2012; 4(5 suppl):S59–S67.

19.

de Souza

, Faintuch

, Valezi

, et al. Gait cinematic analysis in morbidly obese patients. Obes Surg, 2005; 15:1238–1242.

20.

Zdziarski

, Wasser

, Vincent

. Chronic pain management in the obese patient. J Pain Res, 2015; 8:63–77.

21.

Shiri

, Karppinen

, Leino-Arjas

, Solovieva

, Viikari-Juntura

. The association between obesity and low back pain: A meta-analysis. Am J Epidemiol, 2010; 171:135–154.

22.

Khoueir

, Black

, Crookes

, Kaufman

, Katkhouda

, Wang

. Prospective assessment of axial back pain symptoms before and after bariatric weight reduction surgery. Spine J, 2009; 9:454–463.

23.

Lidar

, Behrbalk

, Regev

, et al. Intervertebral disc height changes after weight reduction in morbidly obese patients and its effect on quality of life and radicular and low back pain. Spine (Phila Pa 1976), 2012; 37:1947–1952.

24.

Vincent

, Ben-David

, Conrad

, Lamb

, Seay

, Vincent

. Rapid changes in gait, musculoskeletal pain, and quality of life after bariatric surgery. Surg Obes Relat Dis, 2012; 8:346–354.

25.

Price

, Asenjo

, Christou

, Backman

, Schweinhardt

. The role of excess subcutaneous fat in pain and sensory sensitivity in obesity. Eur J Pain, 2013; 17:1316–1326.

26.

Okifuji

, Hare

. The association between chronic pain and obesity. J Pain Res, 2015; 14:399–408.

27.

Eypasch

, Williams

, Wood-Dauphinee

, et al. Gastrointestinal quality of life index: Development, validation and application of a new instrument. Br J Surg, 1995; 82:216–222.

28.

Quintana

, Cabriada

, López de Tejada

. Traducción y validación del Índice de Calidad de Vida Gastrointestinal (GIQLI). Rev Esp Enferm Dig, 2001; 93:693–699.

29.

Jensen

, Turner

, Romano

, Fisher

. Comparative reliability and validity of chronic pain intensity measures. Pain, 1999; 83:157–162.

30.

Vanderweeën

, Oostendorp

RAB

, Vaes

, Duquet

. Pressure algometry in manual therapy. Man Ther, 1996; 1:258–265.

31.

Chesterton

, Sim

, Wright

, Foster

. Interrater reliability of algometry in measuring pressure pain thresholds in healthy humans, using multiple raters. Clin J Pain, 2007; 23:760–766.

32.

Sánchez-Jiménez

, Cantarero-Villanueva

, Molina-Barea

, Fernández-Lao

, Galiano-Castillo

, Arroyo-Morales

. Widespread pressure pain hypersensitivity and ultrasound imaging evaluation of abdominal area after colon cancer treatment. Pain Med, 2014; 15:233–240.

33.

Fernández-Lao

, Cantarero-Villanueva

, Fernández-de-Las-Peñas

, Del-Moral-Ávila

, Arendt-Nielsen

, Arroyo-Morales

. Myofascial trigger points in neck and shoulder muscles and widespread pressure pain hypersensitivtiy inpatients with postmastectomy pain: Evidence of peripheral and central sensitization. Clin J Pain, 2010; 26:798–806.

34.

, Tsou

, Lee

. Impairment of gastrointestinal quality of life in severely obese patients. World J Gastroenterol, 2014; 14; 20:7027–7033.

35.

Kim

, Kim

. Short-term analysis of food tolerance and quality of life after laparoscopic greater curvature plication. Yonsei Med J, 2016; 57:430–440.

36.

Fezzi

, Kolotkin

, Nedelcu

, et al. Improvement in quality of life after laparoscopic sleeve gastrectomy. Obes Surg, 2011; 21:1161–1167.

37.

Kara

, Genc

, Yildirim

, Ilcin

. Use of tape measure in people with or without back pain in assessment of reposition error. Turk Neurosurg, 2011; 21:290–295.

38.

Melissas

, Kontakis

, Volakakis

, Tsepetis

, Alegakis

, Hadjipavlou

. The effect of surgical weight reduction on functional status in morbidly obese patients with low back pain. Obes Surg, 2005; 15:378–381.

39.

Deyo

, Bass

. Lifestyle and low-back pain. The influence of smoking and obesity. Spine, 1989; 14:501–506.

40.

Bener

, Alwash

, Gaber

, et al. Obesity and low back pain. Coll Antropol, 2003; 27:95–104.

41.

Tsuritani

, Honda

, Noborisaka

, et al. Impact of obesity on musculoskeletal pain and difficulty of daily movements in Japanese middle-aged women. Maturitas, 2002; 42:23–30.

42.

Mortimer

, Wiktorin

, Pernol

, et al. Sports activities, body weight and smoking in relation to low back pain: A population-based care-referent study. Scand J Med Sci Sports, 2001; 11:178–184.

43.

Fernández-Carnero

, Fernández-de-Las-Peñas

, de la Llave-Rincón

, Ge

, Arendt-Nielsen

. Widespread mechanical pain hypersensitivity as sign of central sensitization in unilateral epicondylalgia: A blinded, controlled study. Clin J Pain, 2009; 25:555–561.

44.

Yoo

, Cho

, Lim

, Kim

. Relationships between body mass index, fat mass, muscle mass, and musculoskeletal pain in community residents. Arthritis Rheumatol, 2014; 66:3511–3520.