Frequency of Metabolic Syndrome and Its Components in Patients ...

ORIGINAL ARTICLE

Frequency of Metabolic Syndrome and Its Components in Patients with Carpal Tunnel Syndrome ABSTRACT

Sadaf Iftikhar, Muhammad Athar Javed and Muhammad Naeem Kasuri

Objective: To determine the frequency of metabolic syndrome and its components in patients with carpal tunnel syndrome. Study Design: Case-series. Place and Duration of Study: Department of Neurology, Mayo Hospital, Lahore, from January to June 2012. Methodology: Seventy-five (64 females and 11 males) patients with clinically diagnosed and electrodiagnostically confirmed carpal tunnel syndrome were inducted. Their waist circumference, blood pressure, fasting blood glucose, fasting triglycerides and high density lipoprotein cholesterol levels were recorded. Patients were categorized having metabolic syndrome according to Adult Treatment Panel III criteria, if any 3 were present out of hypertension, elevated fasting triglycerides, reduced high density lipoprotein cholesterol, elevated fasting blood glucose, and elevated waist circumference. Results: Mean age of the patients was 42.04 ±9.31 years, mean waist circumference was 95.32 ±9.03 cm, mean systolic blood pressure was 134.13 ±13.72 mmHg, mean diastolic blood pressure was 89.13 ±8.83 mmHg, mean fasting blood glucose was 94.35 ±21.81 mg/dl, mean fasting triglycerides was 177.48 ±48.69 mg/dl, and mean high density lipoprotein cholesterol was 41.95 ±11.17 mg/dl. Metabolic syndrome was found in 54 (72%) patients including 9 (16.7%) males and 45 (83.3%) females. Out of 75 patients, 54 (72%) had elevated waist circumference, 52 (69.3%) had elevated blood pressure, 19 (25.3%) had elevated fasting blood glucose, 53 (70.6%) had elevated fasting triglycerides and 54 (72%) had reduced high density lipoprotein cholesterol. Highest frequency of metabolic syndrome was found in age range of 40 - 49 years in both genders. Conclusion: Metabolic syndrome is frequently found in the patients with carpal tunnel syndrome. Key Words: Carpal tunnel syndrome. Frequency. Metabolic syndrome.

INTRODUCTION

Carpal tunnel syndrome (CTS) is a collection of characteristic symptoms and signs that occurs following entrapment of the median nerve within the carpal tunnel.1 It is the most frequent nerve entrapment syndrome and encompasses 45% of non-traumatic nerve lesions.2,3 The annual incidence of CTS is 0.1% among adults and overall prevalence is 2.7% among the general population. Female gender and dominant hand affect more frequently.4 CTS can be associated with any condition that causes pressure on the median nerve at the wrist. Some common conditions that can lead to CTS include obesity, oral contraceptives, smoking, corticosteroid use, pregnancy, hypothyroidism, rheumatoid arthritis, osteoarthritis, diabetes mellitis and wrist fractures.5 The most typical symptoms of CTS are pain and paresthesia occurring especially at night in the region of hand supplied by the median nerve. It is very Department of Neurology, King Edward Medical University/ Mayo Hospital, Lahore.

Correspondence: Dr. Sadaf Iftikhar, Department of Neurology, King Edward Medical University / Mayo Hospital, Nila Gumbad, Anarkali, Lahore. E-mail: [email protected] Received: January 02, 2015; Accepted: January 11, 2016. 380

common for patients of CTS to wake up with hypoesthesia and obtain relief by shaking hands. The diagnosis of CTS is based on clinical history, physical examination and electrodiagnostic studies (EDX).

Metabolic syndrome is characterized by hypertension, hyperglycemia, hypertriglyceridemia, reduced high density lipoprotein (HDL) cholesterol, and abdominal obesity. Approximately 20 - 30% population in the world has metabolic syndrome. The components of metabolic syndrome were reported one after another as causes of CTS. Elevated low density lipoprotein (LDL) cholesterol and hyperglycemia were reported as risk factors for CTS in a couple of studies.6,7 Obesity, elevated triglycerides, elevated LDL cholesterol and hypertension were strongly associated with CTS.8 A few studies conducted worldwide have shown a definite association between CTS and metabolic syndrome. In a study by Balci et al.,9 75% patients with CTS were found to have metabolic syndrome. As the two conditions are related and frequently found together, early screening for metabolic syndrome in patients with CTS, can lead the neurologist for referral to a physician. It can help in prevention and management of cardiovascular and other complications associated with metabolic syndrome, thus decreasing the socioeconomic burden of patient and society as a whole.

Journal of the College of Physicians and Surgeons Pakistan 2016, Vol. 26 (5): 380-383

Metabolic syndrome in Carpal tunnel syndrome

The aim of this study was to determine the frequency of metabolic syndrome and its components in patients with CTS.

METHODOLOGY

This case-series descriptive study was conducted on patients with CTS attending the neurology outpatient department (OPD) at Mayo Hospital, Lahore, over a period of 6 months from January to June, 2012. Dominant hands of 75 patients were studied after obtaining the informed consent. Both male and female patients with age range of 18 - 70 years were included in the study. Patients were diagnosed to have CTS clinically and confirmed electrodiagnostically by testing the sensory and motor fibers of both median and ulnar nerves according to American Association of Electrodiagnostic Medicine (AAEM) and American Academy of Neurology (AAN) criteria.10 Abnormal median nerve parameters were recorded by the same electrophysiologist for all patients. Patients with pregnancy, connective tissue disorders, hypothyroidism, hormone replacement therapy, corticosteroid use, rheumatoid arthritis, osteoarthritis and previous wrist fractures were excluded. Patients who had other coexisting diseases, such as cervical radiculopathy, polyneuropathy, thoracic outlet syndrome and trauma history, were also excluded.

After obtaining approval from Hospital Ethical Committee, subjects were assessed for the 5 components of metabolic syndrome, according to Adult Treatment Panel (ATP) III criteria.11 Blood pressure was measured by using a standard mercury sphygmomanometer, after the subject had been seated for at least 2 minutes. The mean value of 2 measurements, taken at least 1 minute apart, was taken. First-phase Korotkoff sound was used for systolic blood pressure (BP) while 5th phase Korotkoff sound was used for diastolic BP. Waist circumference was measured at the narrowest point between umbilicus and bottom of the rib cage with a measuring tape. Blood samples were drawn to check glucose, triglycerides and HDL cholesterol levels after overnight fast of 8 hours. These blood samples were given in the same laboratory at the Department of Neurology, Mayo Hospital, for ascertaining the fasting blood levels. Metabolic syndrome was defined by the presence of 3 or more of the following, according to the ATP-III criteria; waist circumference > 102 cm for males or > 88 cm for females, fasting blood glucose > 100 mg/dl, fasting triglycerides > 150 mg/dl, fasting HDL cholesterol < 40/50 mg/dl (men/women) and blood pressure > 130/85 mmHg. The collected data was analyzed using Satistical Package for Social Sciences (SPSS) version 16 software. Means and standard deviations were calculated for quantitative variables like age, waist

circumference, blood pressure, systolic as well as diastolic, fasting blood glucose, fasting triglycerides, and fasting HDL cholesterol levels. Frequencies and percentages were calculated for qualitative variables like gender and metabolic syndrome. Fisher's exact test was applied to find the p-value which was considered statistically significant when less than 0.05.

RESULTS

Out of 75 patients, there were 64 (85.3%) females and 11 (14.7%) males. Mean age of the patients was 42.04 ±9.31 years. Maximum number of CTS patients with metabolic syndrome was found in age range of 40 - 49 years. Mean waist circumference was 95.32 ±9.03 cm, 39 (52%) patients had waist circumference ranging from 88 - 101 cm. Mean systolic blood pressure was 134.13 ±13.72 mmHg; 42 (56%) patients had blood pressure ranging from 130 - 149 mmHg. Mean fasting blood glucose was 94.35 ±21.81 mg/dl; 45 (60%) patients had fasting blood glucose levels of 80 - 99 mg/dl. Mean fasting triglycerides was 177.48 ±48.69 mg/dl; 32 (42.66%) patients had fasting triglycerides levels of 150 - 199 mg/dl. Mean fasting HDL cholesterol was 41.95 ±11.17 mg/dl; 32 (42.66%) patients had fasting HDL cholesterol levels of 30 - 39 mg/dl (Table I). Metabolic syndrome was found in 54 (72%) patients of CTS, 45 (83.3%) females and 9 (16.7%) males. There was no statistically significant different regarding gender (p = 0.717, Table II). Out of 75 patients, 54 (72%) had elevated waist circumference, 52 (69.3%) had elevated blood pressure, 19 (25.3%) had elevated fasting blood glucose, 53 (70.6%) had elevated fasting triglycerides and 54 (72%) had reduced HDL cholesterol levels. The distribution of variables is shown in Table III.

DISCUSSION

In this study, metabolic syndrome was found in 72% patients with CTS. Metabolic syndrome is a major public health problem and is characterized by abdominal obesity, dyslipidemia (elevated triglycerides and reduced HDL cholesterol levels), hyperglycemia and hypertension.

Balci et al. had shown metabolic syndrome in 75% patients of CTS with mean age of 53.9 ±8.9 years.9 While, metabolic syndrome was found in 72% of this study population with mean age of 42.04 ±9.31 years. Among all patients, the female-to-male ratio was 8.72:1; while in this study it was 5.8:1. There was no difference in frequency of metabolic syndrome among male and female patients of CTS, nearly the same was observed in this study (F:M ratio = 1:1.16). The same diagnostic criteria for metabolic syndrome (i.e. ATP-III criteria) were used in both the studies. The components of metabolic syndrome were reported one after another as causes of CTS. Werner et al.


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Sadaf Iftikhar, Muhammad Athar Javed and Muhammad Naeem Kasuri

Table I: Data for age, waist circumference, blood pressure, fasting blood glucose, fasting triglycerides and fasting HDL cholesterol. Variables

Age (years)

Frequency (n = 75)

Percent (%)

5

6.7

20 - 29

Table II: Crosstabs of gender with metabolic syndrome. Gender

Male

Metabolic syndrome Yes

No

(n = 54)

9 (16.7%)

(n = 21)

2 ( 9.5%)

n =75 (%)

11 (14.7%)

p-value*

0.717

30 - 39

24

32.0

Female

50 - 59

11

14.7

Table III: Frequency of components of metabolic syndrome in carpal tunnel syndrome.

40 - 49 60 - 69 Waist circumference (cms) 81 - 87 88 - 94

95 - 101

102 - 108 109 - 115 116 - 122 Blood pressure systolic (mmHg) 110 - 119

120 - 129

31 4

41.3 5.3

Mean (42.04 ±9.31 S.D) 17 19

20

22.7 25.3 26.7

15

20.0

2

2.7

2

2.7

Mean (95.32 ±9.03 S.D) 8

10

10.7

13.3

130 - 139

22

29.3

150 - 159

11

14.7

140 - 149 160 - 169 170 - 179 Blood pressure diastolic (mmHg)

20 3

26.7 4.0

1

1.3

Mean (134.13 ±13.72 S.D)

70 - 74

5

6.7

80 - 84

16

21.3

90 - 94

14

18.7

75 - 79 85 - 89 95 - 99

100 - 104 Fasting blood glucose (mg/dl) 60 - 79

3

15 6

16

Mean (89.13 ±8.83 S.D)

11

4.0

20.0 8.0

21.3

14.7

80 - 99

45

60.0

120 - 139

1

1.3

100 - 119

140 - 159 180 - 199 Fasting triglycerides (mg/dl)

15

20.0

1

1.3

2

2.7

Mean (94.35 ±21.81 S.D)

100 - 149

22

29.3

200 - 249

14

18.7

150 - 199 250 - 299 300 - 349 Fasting HDL cholesterol (mg/dl)

32 4 3

42.7 5.3

Mean (177.48 ±48.69 S.D)

4.0

10 - 19

1

1.3

30 - 39

32

42.7

50 - 59

8

10.7

20 - 29 40 - 49 60 - 69

382

4

22

Mean (41.95 ±11.17 S.D)

5.3

29.3

45 (83.3%)

19 (90.4%)

Variable

Waist circumference

(> 102 cm in males, > 88 cm in females) Blood pressure > 130/85 mmHg

Fasting blood glucose >100 mg/dl Fasting triglycerides > 150 mg/dl Fasting HDL cholesterol

(< 40 mg/dl in males, < 50 mg/dl in females)

64 (85.3%)

Frequency (%) 54 (72%)

52 (69.3%)

19 (25.3%) 53 (70.6%) 54 (72%)

reported that obese individuals (BMI > 29) are 2.5 times more likely to have CTS compared with slender individuals (BMI < 20).12 Nordstrom et al. demonstrated that a unit increase in body mass index (BMI) increased the risk of CTS by 8%.13 High LDL cholesterol, hypercholesterolemia, hyperglycemia are risk factors for CTS, reported by Kaplan et al.,6 Nakamichi et al.14 and Gulliford et al., respectively.7 Kaplan et al. recruited 70 female and 3 male patients of CTS with mean age of 43.3 ±6.4 years and found mean triglycerides levels of 142.2 ±60.8 mg/dl and mean HDL cholesterol levels of 48.7 ±16.5 mg/dl.6 However, in this study, though mean age i.e. 42.04 ±9.31 was quite comparable but the mean triglycerides levels were elevated i.e. 177.48 ±48.69 mg/dl and mean HDL cholesterol levels i.e. 41.95 ±11.17 mg/dl were lower, in comparison to their study. These differences could be due to differences in ethnicity, geographic distribution, dietary habits and/or lifestyle modifications. Obesity, high LDL cholesterol, high triglycerides, and hypertension – all components of metabolic syndrome – were strongly associated with CTS in subjects aged 30 - 44 years in a study by Shiri et al.;8 these were fairly comparable with the results in this study. They found that men had higher body mass index (BMI), elevated waist circumference and reduced HDL cholesterol levels than women, that was again similar to the results in this study. In another study, Moghtaderi et al. studied 109 female and 19 male patients of CTS and found female gender, increased BMI, and increased waist circumference as the independent risk factors for CTS.15 This study showed quite high frequency of metabolic syndrome in patients of CTS. Further studies should be done to probe into the relationship between CTS and metabolic syndrome, which could help in better management of these syndromes. As the two conditions are related and frequently found together, early screening for metabolic syndrome in patients with CTS can lead the neurologist for referral to an endocrinologist.


Metabolic syndrome in Carpal tunnel syndrome

The present study has some limitations. Firstly, as this study was a hospital-based study conducted on patients belonging to lower socio-economic status having a different clinical and risk factor profile, these results cannot be applied to the general population. Secondly, large sample size would certainly improve precision of the results. Lastly, having a control group would definitely make such study stronger.

CONCLUSION

Metabolic syndrome is frequently found in CTS patients, almost equally affecting both the genders. Screening of CTS patients for metabolic syndrome can be a costeffective healthcare measure to reduce the morbidity and mortality, associated with cardiovascular and other complications of metabolic syndrome. It is recommended that further studies should be carried out to probe the potential relationship between CTS and metabolic syndrome. Disclosure: This is a dissertation-based article.

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