Metabolic Abnormalities observed in Osteoarthritis of Knee: A single center experience

Original Article

Metabolic abnormalities observed in osteoarthritisof knee: A single center experience

Alakes Kumar Kole a,*, Rammohan Roy b, Dalia Chanda Kole c

aAssociate Professor, Department of Medicine, North Bengal Medical College & Hospital, Darjeeling, West Bengal,

IndiabClinical Tutor, Department of Medicine, Infectious Diseases Hospital, 57 Beliaghata Main Road, Kolkata 10, IndiacSenior Consultant, B P Poddar Medical Research & Hospital, New Alipore, Kolkata, India

a r t i c l e i n f o

Article history:

Received 27 June 2013

Accepted 24 September 2013

Available online xxx

Keywords:

Osteoarthritis of knee

Metabolic abnormalities

Risk factors

a b s t r a c t

Background: Osteoarthritis is the most common type of joint disease and nowadays obesity-

metabolic syndrome is one of the major risk factors.

Aims and objectives: To observe the different metabolic abnormalities in patients with knee

osteoarthritis.

Patients & methods: A total of 336 patients suffering from knee osteoarthritis were evaluated

with special reference to different metabolic abnormalities.

Results: The mean age was 45.8 � 14.4 years with male: female ratio was 1:1.2. The meta-

bolic abnormalities observed were e hyperuricemia in 50 (14.9%), metabolic syndrome in

43 (12.8%), obesity with dyslipidemia in 28 (8.3%), diabetes with dyslipidemia in 25 (7.4%),

obesity in 21 (6.3%), hypothyroidism in 14 (4.2%), diabetes in 13 (3.9%) and dyslipidemia in

10 patients (3%). It had been observed that clustering of metabolic abnormalities were

present in younger patients.

Conclusion: Osteoarthritis is not only a source of discomfort or misery but also may be

associated with various metabolic abnormalities, which are the future predictors of car-

diovascular events.

Copyright ª 2013, Indraprastha Medical Corporation Ltd. All rights reserved.

1. Introduction

Osteoarthritis (OA) has become amajor public health problem

not only because of increasing prevalence worldwide (about

21 million people affected in the United States) but also

frequent association with cardiovascular diseases-the leading

cause of death in the industrialized countries.1 Osteoarthritis

changes is seen in almost all people above 75 years of age

whereas at the age of 18e24 years about 7% of men and 2% of

women usually show signs of osteoarthritis changes.2 Recent

concept is that OA is not merely a disease related to aging or

mechanical stressof joints, ratherametabolicdisorder sharing

similar biochemical as well as inflammatory profile contrib-

uting to both the initiation and progression of the disease

process.1,3 Hence ‘metabolic osteoarthritis’ may be considered

as a subtype of OA and also the fifth component of metabolic

* Corresponding author. Resident address: Victoria Greens, Flat-A3/204, 385 Garia Main Road, Kolkata 700084, West Bengal, India.Tel.: þ91 (0) 9830056291.

E-mail addresses: dralakeskole72@gmail.com, dralakeskole@yahoo.co.in (A.K. Kole), royrammohan@yahoo.com (R. Roy), drda-liachanda77@yahoo.co.in (D.C. Kole).

Available online at www.sciencedirect.com

journal homepage: www.elsevier .com/locate/apme

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Please cite this article in press as: Kole AK, et al., Metabolic abnormalities observed in osteoarthritis of knee: A single centerexperience, Apollo Medicine (2013), http://dx.doi.org/10.1016/j.apme.2013.09.001

0976-0016/$ e see front matter Copyright ª 2013, Indraprastha Medical Corporation Ltd. All rights reserved.http://dx.doi.org/10.1016/j.apme.2013.09.001

syndrome.4 It had been reported that obesity is one of the

majormodifiable risk factors attributing to the development of

knee osteoarthritis (elevated adipokines) by inducing the

expression of proinflammatory factors as well as degradative

enzymes leading to the inhibition of cartilagematrix synthesis

and stimulation of subchondral bone remodeling.5 Hypergly-

cemia (advanced glycation end-products), by oxidative stress

and also by inducing low-grade systemic inflammation, is

responsible for cartilage damage, whereas dyslipidemia may

initiate development of OA due to abnormal lipid metabolism

(ectopic lipid deposition). Moreover, hypertension can cause

subchondral ischemia compromising nutrient exchange and

triggering bone remodeling leading to osteoarthritis.Metabolic

syndrome was reported to be more prevalent in younger

individuals suffering from knee osteoarthritis regardless of

sex or race and the development of osteoarthritis at the age

of 44 years was associated with a five fold increased risk of

metabolic syndrome.6 Moreover, presence of more than one

metabolic risk factors was associated with more chances of

development and also progression of knee osteoarthritis.7

A recent study showed that patients suffering from knee OA

had twofold increased risk of availing sick leave and also

40e50% increased risk of disability pension benefit compared

to the general population.8 Moreover osteoarthritis, particu-

larly in the younger individuals, is really a source of discomfort

and misery, often due to the fact that it prevents and hinders

an otherwise healthy individual taking part in activities they

might usually enjoy due to its significant impact on quality

of life.9

The objective of this study was to observe different

metabolic abnormalities in patients suffering from knee

osteoarthritis.

2. Patients and methods

This was a cross sectional observational study done in North

Bengal Medical College & Hospital, Darjeeling, India from

January ’2009 to January ’2011. A total number of 342 patients

suffering from knee osteoarthritis (diagnosed as per the ACR

criteria) were randomly selected from rheumatology clinic and

six of themwere excluded because of recent history of trauma

to knee joint. The enrolled patients were evaluated in respect

to their complaints, occupation, food habits, body mass index

(BMI), waist hip ratio, blood pressure, and any history of

operation or injury involving knee joints in past or any

congenital bony abnormality. Blood biochemistry including

fasting blood glucose, serumuric acid, lipid profile and thyroid

function tests were done. Consent for this study was taken

from each patient and ethical approval done. Data were

collected and analyzed in respect to different metabolic ab-

normalities and metabolic syndrome was diagnosed as per

NationalCholesterol EducationProgram(NCEP-ATPIII) criteria.

3. Results

In this study themean agewas 45.8� 14.4 yearswith themale:

female ratio was 1:1.2 and the mean BMI was 24.34 � 4.45 kg/

m2. The occupation of these patients were office workers -112

(33.3%), shopkeepers -95 (28.2%), labors -39 (11.6%), retired

persons -33 (9.8%), farmers -27 (8%), house wives -21 (6.2%)

and students -9 (2.7%). Majority of these patients were

observed to have history of consumption of high calorie diet

and less physical activity. The different metabolic abnormal-

ities observed were e metabolic syndrome in 43 (12.8%),

obesity and dyslipidemia in 28 (8.3%), diabetes and dyslipi-

demia in 25 (7.4%), obesity in 21 (6.3%), hypothyroidism in

14 (4.2%), diabetes in 13 (3.9%) and dyslipidemia in 10 pa-

tients (3%) [Table 1]. The mean triglyceride level was

221.24 � 58.56 mg/dl, HDL was 32 � 4.2 mg/dl, LDL level was

112 � 24.56 mg/dl andmean uric acid was 6.8 ± 1.3 mg/dl. The

other co morbidities/ inflammatory diseases /events observed

were e hypertension in 36 (10.7%), past history of knee joint

injury/operation in 19 (5.6%), inflammatory joint diseases in 12

cases (3.6%) [rheumatoid arthritis in 8, ankylosing spondylitis

in 3 and mixed connective tissue disease in one].

4. Discussion

In this study it had been observed that metabolic abnormal-

itieswere present in different combinations in a total of 46% of

patients suffering from knee OA and importantly clustering of

these metabolic abnormalities were present below 50 years of

age group (26%) which was epidemiologically significant. Hy-

peruricemia was the most common metabolic abnormality

observed in this study and it had been reported that high

serum uric acid was associated with metabolic syndrome and

its components.10 Metabolic syndrome was detected in 12.8%

patients and they were mainly office workers or shopkeepers

with sedentary lifestyle. Moreover, it had been also observed

that majority of these patients had suffered much from pain,

stiffness and restricted movement of knees requiring

repeated outpatient visit, long absence from works particu-

larly in younger patients and also hampering social activities.

Diabetes and primary hypothyroidism were the two major

endocrine disorders observed in 3.9% and 4.2% cases of knee

OA in this study and strict control of these abnormalities are

essential to control OA. Though in this present study meta-

bolic abnormalities were not so uncommon but more popu-

lation based studies are needed to establish whether these are

merely associated or as risk factors for knee OA.

Hence, maintaining ideal body weight along with regular

exercise and consumption of low calorie/high fiber diet are

all may be considered as primordial prevention for develop-

ment of metabolic abnormalities. Moreover continuous

Table 1 e Different metabolic abnormalities in patientswith knee OA.

Risk factors No of patients (%)

Hyperuricemia 50 (14.9%)

Metabolic syndrome 43 (12.8%)

Obesity þ dyslipidemia 28 (8.3%)

Diabetes þ dyslipidemia 25 (7.4%)

Obesity 21 (6.3%)

Hypothyroidism 14 (4.2%)

Diabetes 13 (3.9%)

Dyslipidemia 10 (3%)

a p o l l o m e d i c i n e x x x ( 2 0 1 3 ) 1e32

Please cite this article in press as: Kole AK, et al., Metabolic abnormalities observed in osteoarthritis of knee: A single centerexperience, Apollo Medicine (2013), http://dx.doi.org/10.1016/j.apme.2013.09.001

counseling with reinforcement for weight loss in already

obese individuals alongwith regularmetabolic screening and

appropriate management of already developed metabolic

abnormalities are all the essential steps in patients suffering

from osteoarthritis of knee to decrease future cardiovascular

events and also possibly the development and/or progression

of osteoarthritis.

Conflicts of interest

All authors have none to declare.

r e f e r e n c e s

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Please cite this article in press as: Kole AK, et al., Metabolic abnormalities observed in osteoarthritis of knee: A single centerexperience, Apollo Medicine (2013), http://dx.doi.org/10.1016/j.apme.2013.09.001

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