Table 1: Summary of the studies.

AuthorsYearTendinopathyStudy designNumber of patientsAge in years (range)Measures of obesityRelevant resultsConclusions of the studyAssociation

Wendelboe et al. [14]2004Rotator cuffFrequency-matched case-control study
Prognostic study,
Level II
311 RCR cases versus 993 controls(53–77)BMIOR: 1.9 (95% CI: 1.1–2.2) for males and 2.4 (1.4–4.2) for females with BMI ≥ 35.
OR: 3.1 (95% CI: 1.3–7.6) for males and 3.5 (1.8–6.9) for females with BMI ≥ 35.
Risk directly correlated with the grade of obesity for both men () and women ()
Obesity increases risk to need RCRYes

Rechardt et al. [19]2010Rotator cuffCross-sectional study (population study)6,237 of which chronic 28 (2.8%) with RC tendinitis50.8 for men, 52.9 for women (>30)BMI,
waist circumference,
waist-to-hip ratio
WC 94.0–101.9 cm and RC tendinitis
OR: 2.0 (1.1–3.5) in men
Increased WC is associated with chronic RC tendinitis in menPartial

Titchener et al. [23]2014Rotator cuffRetrospective case-control, treatment study
Level III
5,000 cases of RC disease versus 5,000 controls
(BMI calculated in 3,385 of cases (67.7%) and 3,050 (61.0%) of controls)
55
(interquartile range 44–65)
BMI BMI 25.1–30 (overweight) and RC disease OR: 1.23 (1.10–1.38)
BMI 30.1–40 (obese) and RC disease OR: 1.25 (1.09–1.44)
BMI > 40 (morbidly obese) no increased risk
After adjustment for consultation rate, the effect persisted only in the BMI 25.1–30 (overweight) group OR: 1.15 (1.02–1.31)
Significant association only for patients who are slightly overweight (BMI 25–30)
Impossible to differentiate comorbid factors such as diabetes mellitus, atherosclerosis, and hyperlipidemia
Partial

Titchener et al. [24]2013Epicondylitis (lateral and medial)Retrospective case-control, treatment study
Level III
4998 versus 4998 controls
(BMI calculated in 3,449 of cases (69%) and 3,049 (61.0%) of controls)
49
(interquartile range 42–56)
BMI BMI > 40 and lateral epicondylitis OR: 1.41 (1.01–1.97)
The effect disappeared when BMI was adjusted for consultation rate
Obesity is not associated with epicondylitisNo

Descatha et al. [28]2013Epicondylitis (lateral and medial)Case-series (longitudinal study)
Level IV
699 workers with no symptoms at baseline.
At 36 months: 48 suffered from medial or lateral epicondylitis (6.9%), 34 from lateral epicondylitis (4.9%), 30 from medial epicondylitis (4.3%), and 16 from both
38.1 ± 9.3 (20–66)BMIBMI > 30 and lateral epicondylitis: univariate analyses OR: 2.4 (1.2–4.8), multivariate analyses OR: 1.8 (0.8–3.9).
No association for medial epicondylitis
Obesity is associated only with lateral epicondylitisPartial

Shiri et al. [20]2006Epicondylitis (lateral and medial)Cross-sectional study (population study)4,783 of the initial 5,871 (81.5%)
67 with lateral epicondylitis (1.3%) and 19 with medial epicondylitis (0.4%)
46.3 ± 9.6 (30–64)BMI,
waist circumference
Only in women
WC > 100 cm and medial epicondylitis OR: 2.7 (1.2–6.0)
BMI > 30 kg/m2 and medial epicondylitis OR: 1.9 (1.0–2.7)
No association for lateral epicondylitis
Obesity is associated with medial epicondylitis.Partial

Alvarez-Nemegyei [25]2007Pes anserinusRetrospective case-control study
Level III
22 cases of tendinopathy versus 38 controls62.1 ± 11.5 for cases, 59.8 ± 9.4 for controlsBMIObesity: case 16/22 (72.7), controls 21/38 (55.3), nonsignificantNo associationNo

Taunton et al. [27]2002Patellar tendonRetrospective case-control study
Level III
96 cases versus 1906 controls34.3Weight,
BMI
No associationNo associationNo

Frey and Zamora [21]2007Achilles, posterior tibial, and peroneal tendon Cross-sectional study (population study)1411 of which
208 with tendinitis/tendinosis
>18BMI123 (65.4%) of the overweight/obese subjects had a diagnosis of tendinitis compared to 65 (34.6%) normal subjects.
BMI > 25 and tendinitis OR: 1.923 (1.39–2.66)
Being overweight or obese significantly increased the chances of tendinitisYes

Holmes and Lin [26]2006AchillesRetrospective case-control study,
Level III
82 cases49.5 (27–77)BMIObesity was statistically associated with Achilles tendinopathy for women and for men, respectivelyObesity is one of the etiological factors of the Achilles tendinopathyYes

Gaida et al. [22]2010AchillesPopulation-based study (cross-sectional study)298 cases (127 men, 171 women) asymptomatic Achilles tendinopathy in 17 men (13%) and 8 women (5%) ().Men 38.3 ± 12.2
Women 36.5 ± 10.5
Fat distribution (android/gynoid fat mass ratio and upper body/lower body fat mass ratio) determined using WC, WHR, and dual-energy X-ray absorptiometryMen with Achilles tendinopathy had greater WHR (0.926 ± 0.091, 0.875 ± 0.065, ), higher android/gynoid fat mass ratio (0.616 ± 0.186, 0.519 ± 0.142, ), and higher upper body/lower body fat mass ratio (2.346 ± 0.630, 2.022 ± 0.467, ).
Women with tendinopathy had less total fat (17196 ± 3173 g, 21626 ± 7882 g, ), trunk fat (7367 ± 1662 g, 10087 ± 4152 g, ), and android fat (1117 ± 324 g, 1616 ± 811 g, ). They had lower central/peripheral fat mass ratios (0.711 ± 0.321 g, 0.922 ± 0.194 g, ) than women with normal tendons
Men with Achilles tendinopathy had a central fat distribution.
Women had a peripheral fat distribution.
Yes

Scott et al. [15]2013AchillesFrequency-matched case-control study
Prognostic study,
Level II
197 cases versus 100 controlsCases: 52.77 ± 11.8 (21–82)
Controls: 42.74 ± 12.1 (21–78)
BMISignificant difference in BMI:
34.69 ± 7.54 (17.9–75.9) versus 30.56 ± 7.55 (19.7–61-5)
Patients with Achilles tendinopathy exhibited a significant higher BMI than controlsYes

Klein et al. [16]2013AchillesFrequency-matched case-control study
Prognostic study,
Level II
472 cases versus 472 controlsCases: 51.2 ± 13.5 (16–88)
Controls: 52.0 ± 14.3 (18–88)
BMIOR:
2.60, 95% CI = 1.87–3.61;
3.81, 95% CI = 2.57–5.63;
3.77, 95% CI = 2.24–6.34;
6.56, 95% CI = 3.18–13.55
For BMI: 25.0–29.9, 30.0–34.9, 35.0–39.9, and >40.0, respectively
BMI plays a role in the development of Achilles tendinopathy Yes

Taunton et al. [27]2002AchillesRetrospective case-control study,
Level III
96 cases versus 1906 controls40.7Weight,
BMI
No associationNo associationNp

Taunton et al. [27]2002Plantar fasciaRetrospective case-control study,
Level III
158 cases versus 1846 controls41.8Weight,
BMI
Weight >60 kg in female OR: 0.378 (0.203–0.706)Women with a body weight greater than 60 kg were at increased risk of experiencing plantar fasciitisPartial

Irving et al. [17]2007Chronic plantar heel Frequency-matched case-control study
Prognostic study,
Level II
80 cases versus 80 controls52.3 ± 11.7BMISignificantly greater BMI for CPHP group (29.8 ± 5.4 kg/m2 versus 27.5 ± 4.9 kg/m2; ) 
CPHP were more likely to be obese (OR: 2.9, CI: 1.4–6.1, )
Obesity is associated with chronic plantar heel painYes

Frey and Zamora [21]2007Plantar fasciaCross-sectional study (population study)1411 of which
189 with plantar fasciitis
>18BMI208 affected by plantar fasciitis
BMI > 25 and plantar fasciitis OR: 1.4 (1.016–1.93)
If the subjects were overweight or obese, there was an increased likelihood, although not significant, of plantar fasciitis No

Riddle et al. [18]2003Plantar fasciaFrequency-matched case-control study
Prognostic study,
Level II
50 cases versus 100 controls49 ± 11 (31–85)BMIBMI > 30 OR: 5.6 (CI: 1.9–16.6) compared with the BMI ≤ 25 kg/m2Obesity appears to be independent risk factor for plantar fasciitis.Yes

BMI: body mass index; WC: waist circumference; WHR: waist-to-hip ratio; OG: group of obese patients; CG: control group; RC: rotator cuff; RCR: rotator cuff repair; CPHP: chronic plantar heel pain; OR: odds ratio; CI: confidence interval; and n.r.: not reported.