Journal of Diabetes Research and Endocrinology Open Access

Keywords

Type 2 diabetes; Glucose tolerance; Metabolic syndrome; Triglycerides

Abbreviations

BMI: Body Mass Index; DBP: Diastolic Blood Pressure; HDL: High Density Lipoprotein; IDF: International Diabetes Federation; MetS: Metabolic Syndrome; NCEP ATP-III: National Cholesterol Education Program Adult Treatment Panel III; SBP: Systolic Blood Pressure; TG: Triglycerides; WC: Waist Circumference; WHO: World Health Organization

Introduction

Type 2 diabetes is a complex disorder of impaired glucose tolerance, insulin resistance and lipid abnormalities. There is a rapid increase in the prevalence of diabetes due to modernization and urbanization that has resulted in a substantial burden on the healthcare services [1]. The top three countries with highest rates of diabetes include India, China and United States with alarming rates of prevalence of diabetes [2]. There is a sharp increase in the population with diabetes from 19 million in 1995 to 66.8 million in 2015 in India which is predicted to increase to 123.5 million by 2040. The crude prevalence rate of diabetes in urban areas is about 9% and the prevalence in rural areas has also increased to around 3% of the total population [3].

Metabolic syndrome is defined as a cluster of cardiovascular risk factors which include dysglycemia, central obesity, hypertension and dyslipidemia. There are different definitions of metabolic syndrome given by WHO [4], NCEP ATP-III [5] and IDF [6] with little variations in each. Type 2 diabetes and metabolic syndrome are both heterogeneous and complex conditions due to the interaction between environmental and genetical factors and in the population with type 2 diabetes, nearly 70-80% are diagnosed with metabolic syndrome [7-9].

There is growing evidence that like diabetes, metabolic syndrome besides resulting in macrovasular complications also causes microvascular complications in type 2 diabetes patients [10-12]. The risk of macrovascular and microvascular complications increases with metabolic syndrome in combination with diabetes due to associated dyslipidemia, hypertension and obesity [11]. The studies in American and European populations have shown the correlation between metabolic syndrome and macro- and microvascular complications, in patients with diabetes [13-15].

Most of the studies have looked into the metabolic syndrome prevalence in general population [16-19]. There are few studies that have calculated the prevalence in the diabetic population [13,20-21] but there is complete paucity of such studies in the population of Northern Punjab.

Therefore, the present study aimed at determining the prevalence of metabolic syndrome in type 2 diabetes patients according to IDF criteria [6] and the risk factors associated with the metabolic syndrome.

Methods

A total of 680 type 2 diabetic patients (340 males and 340 females) ranging in age from 35 to 60 years and belonging to North-West region of Punjab were included in the study. Informed consent was obtained from the participants after explaining the procedure and the objectives of the study and complete confidentiality of the collected data was ensured to them. The study protocol was reviewed and approved by the Institutional Ethical Committee of Punjabi University, Patiala.

A prospective study was planned to analyze the pattern of dyslipidemia in diabetic patients attending the Diabetes Clinics from different hospitals and clinics of Malwa region of Punjab over a period of 2 years (July 2013 to June 2015). The study population included already diagnosed, on treatment diabetic patients. The patients who already had history of CAD or cerebrovascular accident (CVA) or having other major chronic systemic disorders were not included in the study.

MetS was defined using the International Diabetes Federation [6] consensus group guidelines as abdominal obesity (waist circumference ≥ 90 cm for men and ≥ 80 cm for women) plus two or more of the following risk factors: blood pressure ≥ 130/85 mm Hg, fasting plasma glucose (100 mg/dl) or pre-existing diabetes, serum triglycerides (≥ 150 mg/l) and HDL levels for men (<40 mg/ dl) and women (<50 mg/dl).

Anthropometric measurements including weight, height and waist circumference were obtained using standardized techniques. The blood pressure was recorded, in the sitting position, in the right arm to the nearest 2 mm Hg using the mercury sphygmomanometer (Diamond Deluxe BP apparatus, Pune, India). Two readings were taken, five minutes apart, and their mean was taken as the blood pressure.

The overnight fasting blood samples were taken with the help of trained technician after eight hours of overnight fasting to estimate the plasma glucose and serum lipids. The biochemical analysis was done on Med-o-Source, automated analyzer. The total serum cholesterol (CHODPOD method), HDL (after protein precipitation CHOD-POD method) and serum triglycerides (CHOD-POD) were estimated.

A computerized database was created for all the records. A statistical package for the Social Sciences-SPSS (version 16.0) was used for statistical analysis. All the data were expressed as mean ± S.D or as percentage. The statistical significance was assumed at p-value <0.05. The student t-test was used to analyse the differences between patients with MetS and without MetS and chi square analysis was performed to find out the significant differences in the proportions.

Results

The study revealed significant gender differences with higher prevalence of metabolic syndrome in females (43.5%) as compared to males (34.1%). On the basis of BMI (Table 1), 27.4% males were overweight; 55% were obese and only 17.6% had normal BMI whereas in the females, 15.6% were overweight; 75.9% were obese and only 8.5% had normal BMI values. Higher rates of metabolic syndrome were observed in older age groups in males and middle age groups in females (Table 2).

Variables	Males	Females	χ2	p value
Age (years) 31-40 41-50 51-60 61-70	19 (5.59%) 127 (37.53%) 157 (46.18%) 37 (10.88%)	67 (19.71%) 120 (35.29%) 72 (21.18%) 81 (23.82)	5.12	0.05
BMI (kg/m2) Normal Overweight Obese	60 (17.65%) 93 (27.35%) 187 (55%)	29 (8.53%) 53 (15.59%) 258 (75.88%)	29.92	<0.0001
Metabolic syndrome Absent Present	224 (65.88%) 116 (34.12%)	192 (56.47%) 148 (43.53%)	5.95	0.01

Table 1: Age distribution and gender differences in the prevalence of obesity and metabolic syndrome in type 2 diabetes patients.

Age Group	Females	Males
31-40	43 (29.1%)	8 (6.9%)
41-50	43 (29.1%)	52 (44.8%)
51-60	29 (19.5%)	52 (44.8%)
61-70	33 (22.3%)	4 (3.5%)

Table 2: Prevalence of Metabolic Syndrome across different age groups.

The values of waist circumference (WC), TG, BMI, SBP and DBP were significantly greater in males with MetS as compared to males without MetS and the differences were statistically significant (Table 3). In females with MetS, WC, TG, DBP were significantly higher and HDL was significantly lower as compared to females without MetS (Table 4).

Variables	With MetS (Mean ± SD)	Without MetS (Mean±SD)	t-value
Age (years)	50.74 ± 5.13	53.05 ± 7.84	1.68
Duration of Diabetes (years)	6.38 ± 4.81	7.07 ± 4.93	0.64
Waist Circumference (cm)	98.22 ± 6.22	90.75 ± 8.00	4.53**
BMI (kg/m2)	26.49 ± 2.30	24.99 ± 2.92	2.48*
Fasting Blood Sugar (mg/dl)	242.52 ± 97.44	256.33 ± 118.52	0.59
Triglycerides (mg/dl)	242.70 ± 91.16	179.74 ± 89.50	3.16*
HDL (mg/dl)	53.14 ± 14.11	53.56 ± 12.93	0.14
SBP (mm/Hg)	131.71 ± 13.03	125.03 ± 9.96	2.72*
DBP (mm/Hg)	90.80 ± 11.48	83.16 ± 9.56	3.36**

*represents statistically significant at p<0.05.
**represents statistically significant at p<0.01.

Table 3: Demographic, anthropmetric and biochemical indices in type 2 diabetes males with and without metabolic syndrome.

Variables	With MetS (Mean ± SD)	Without MetS (Mean ± SD)	t-value
Age (years)	49.96 ± 11.01	50.92 ± 9.99	0.38
Duration of Diabetes (years)	6.04 ± 3.41	5.98 ± 3.64	0.07
Waist Circumference (cm)	90.94 ± 7.45	85.03 ± 10.61	2.72*
BMI (kg/m2)	28.18 ± 4.15	27.03 ± 4.52	1.12
Fasting Blood Sugar (mg/dl)	208.46 ± 93.84	183.93 ± 121.87	0.96
Triglycerides (mg/dl)	197.69 ± 87.65	129.01 ± 74.49	3.49*
HDL (mg/dl)	45.67 ± 13.49	54.16 ± 14.71	2.52*
SBP (mm/Hg)	133.16 ± 16.22	133.08 ± 17.16	0.02
DBP (mm/Hg)	85.00 ± 11.10	79.57 ± 8.53	2.32

*represents statistically significant at p<0.05.
**represents statistically significant at p<0.01.

Table 4: Demographic, anthropometric and biochemical indices in type 2 diabetes females with and without metabolic syndrome.

In females, central obesity (81.7%) and hypertension (64.7%) followed by hypertriglyceridemia (68.1%) were the driving forces for metabolic syndrome whereas in males, it were hypertriglyceridemia (68.1%) and central obesity (67.3%) followed by hypertension (59.4%) (Table 5).

	Males	Females
Increased FBS	328 (96.5)	312 (91.7)
Central obesity	232 (67.3)	278 (81.7)
Increased TG	232 (68.1)	177 (52.1)
Decreased HDL	67 (19.71)	158 (46.5)
Hypertension	202 (59.4)	220 (64.7)

Table 5: Gender differences in the prevalence of MetS risk factors.

The type 2 diabetes male patients with metabolic syndrome had clustering of central obesity and diabetes with any two other risk factors and in females; it was central obesity and diabetes with any one risk factor. Only few individuals had clustering of all the risk factors (Table 6).

Components of MetS	Males	Females
Any 1	78 (22.9%)	124 (36.4%)
Any 2	111 (32.6%)	105 (30.8%)
Any 3	4 (1.1)	42 (12.4%)

+ Any 1, Diabetes + Obesity + Any of hypertension, reduced HDL or elevated triglyceride;
+ Any 2, Diabetes + Obesity + Any two of hypertension, reduced HDL or elevated triglyceride;
+ Any 3, Diabetes + Obesity + All three of hypertension, reduced HDL or elevated triglyceride.

Table 6: Pattern of Clustering of components of metabolic syndrome.

Discussion

Metabolic syndrome has been on the rise, contributing to the increasing prevalence of non-communicable disorders such as cardiovascular diseases and type 2 diabetes mellitus. But there are few studies that have reported the prevalence of metabolic syndrome in diabetes population. In the present study, attempt has been made to study the prevalence of metabolic syndrome risk factors in diabetes population of North-West Punjab.

The overall prevalence of the metabolic syndrome (MetS) in the present study was 41.25% (43.5% in females and 34.1% in males). The prevalence of MetS as defined by IDF was found to be 71.7% and 60.4% as defined by NCEP-ATP III in a study among diabetes patients in Cameroon [22]. Another reported an overall MetS prevalence of 51% (44% in men and 56% in women) based on the WHO criteria [23]. Makuyana et al. [24] reported prevalence rate of MetS to be 43% in diabetic subjects in a tertiary care diabetes clinic. Kelliny et al. [25] reported MetS rates of 66.8%, 85.5%, 74% among men and 87.1%, 79.7%, 93% among women, according to the NCEP-ATP III, WHO and IDF criteria, respectively, in some parts of Africa and rates of 46% and 74% in Black and White South Africans respectively based on the IDF criteria [26].

The differences could be due to the variable criteria used in defining MetS as well as ethnic differences.

In the present study, metabolic syndrome was found to be more common in females suffering from type 2 diabetes as compared to their male counterparts. Similar findings have been reported by many studies in the developing countries [27-30]. The high prevalence of the MetS found among women in the present study could be due to the fact that a significant proportion of women had abdominal obesity which is one of the components of the MetS according to the IDF criteria used in the study.

The variable rates of the components of the MetS were observed. Similar to the findings of Ogbera [31] and Kelliny et al. [25] abdominal obesity was one of the components of the MetS that occurred frequently. However, contrary to their findings, it was more prevalent in women than in men. The most common abnormality among women was central obesity and men were more likely to have hypertension and hypertriglyceridemia. The present study reported that the age group of 40-60 years had a higher prevalence of metabolic syndrome which is in accordance with the study done in South Asians [32].

It is evident from this study that metabolic syndrome is quite prevalent in our type 2 diabetes patients like in other parts of the world.

Limitations of the Study

The main limitation of our study was the average size of the sample, which may have limited the power of the results. This study took place in one particular region and may limit the extrapolation to other regions of Punjab.

Conclusion

Frequency of MetS was found to be significantly high in this study with female preponderance. All the components, except hypertension were more frequent in females. It is very important to diagnose it early to prevent the life threatening cardiovascular complications.

Recommendations

To curb the diabetes epidemic, primary prevention through the promotion of a healthy diet and lifestyle should be a global public policy priority. Diabetic patients with metabolic syndrome need more aggressive approach in management so as to decrease the incidence of cardiovascular complications.

Funding Source

The present study was carried out from the grant received from the University Grants Commission (UGC), New Delhi for carrying out Major Research Project sanctioned to the first author.

Acknowledgement

The authors thank all the subjects for their full participation in the study. Without their cooperation, the study would not have been completed.

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