Abstract

The aim of the study is to evaluate the impact of sex as variable in measuring waist/hip ratio as risk factor predictor in patients with metabolic disease. A longitudinal cross sectional study conducted on 234 patients with metabolic syndrome during 6 months duration, demographic data like Age and gender were recorded for each patient, other measures like waist circumference, hip circumference, height, weight, according to standards and body mass index and waist/hip ratio also calculated, blood tests including fasting blood sugar, lipid profile were also measured to the sample. Data were analyzed using descriptive statistics (frequencies and percentages) and analytic statistics (person correlation two ways (ANOVA) by SPSS, version 11. p<0.05 was considered statistically significant the mean age for male was 45.73(±7.83) years while for female was 46.92(±7.83) years. There was significant difference with W/H ratio 0.007 (-0.05 to -0.008) for both sexes (91.03%) of the total sample were having Diabetes mellitusand (63.25%) of the sample were having hypertension. Most of the participants (85.74%) had no physical activity. A positive correlation was obtained between W/H ratio and BMI, FBS, TG andHDL in male participants. the mean of W/H ratio in both gender as cross classified with Physical Exercise were the difference in mean is significantly associated WHR was significantly associated with the risk of incident CVD events. These simple measures of abdominal obesity should be incorporated into CVD risk assessments.

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INTRODUCTION

Metabolic syndrome is a combination of medical disorders that increase the risk of developing cardiovascular disease and diabetes. It affects one in five people and prevalence increases with age. The exact mechanisms of the complex pathways of metabolic syndrome are not yet completely known. The pathophysiology is extremely complex and has been only partially elucidated. Most patients are older, obese, sedentary and have a degree of insulin resistance. The most important factors in order are weight, genetics (Pollex and Hegele, 2006; Poulsen et al., 2001; Groop, 2000; Bouchard, 1995) aging and Sedentary lifestyle, i.e., low physical activity and excess caloric intake (Katzmarzyk et al., 2003).

Central adiposity is a key feature of the syndrome, reflecting the fact that the syndrome's prevalence is driven by the strong relationship between waist circumference and increasing adiposity. However, despite the importance of obesity, patients that are of normal weight may also be insulin-resistant and have the syndrome (Fauci, 2008). The metabolic syndrome has been associated with several obesity-related disorders including fatty liver disease, chronic renal disease, polycystic ovarian syndrome, obstructive sleep apnea and increase risk of cognitive decline and dementia (Grundy et al., 2004).

Physical inactivity is a predictor of CVD events and related mortality. Many components of the metabolic syndrome are associated with a sedentary lifestyle, including increased adipose tissue (predominantly central); reduced HDL cholesterol and a trend toward increased triglycerides, blood pressure and glucose in the genetically susceptible. Compared with individuals who watched television or videos or used their computer for >1 h daily, those that carried out these behaviors for >4 h daily have a twofold increased risk of the metabolic syndrome (Lara-Castro et al., 2007).

The metabolic syndrome affects 44% of the U.S. population older than age 50. A greater percentage of women older than age 50 have the syndrome than men. The age dependency of the syndrome's prevalence is seen in most populations around the world (Renaldi et al., 2009).

It is estimated that the large majority (~75%) of patients with type 2 diabetes or Impaired Glucose Tolerance (IGT) have the metabolic syndrome. The presence of the metabolic syndrome in these populations is associated with a higher prevalence of CVD than found in patients with type 2 diabetes or IGT without the syndrome (Lara-Castro et al., 2007) Hypoadiponectinemia has been shown to increase insulin resistance (Lara-Castro et al., 2007) and is considered to be a risk factor for developing metabolic syndrome (WHO, 2000).

The approximate prevalence of the metabolic syndrome in patients with Coronary Heart Disease (CHD) is 50% with a prevalence of 37% in patients with premature coronary artery disease (age 45), particularly in women. With appropriate cardiac rehabilitation and changes in lifestyle (e.g., nutrition, physical activity, weight reduction and in some cases, Drugs), the prevalence of the syndrome can be reduced (Lara-Castro et al., 2007).

Lipo dystrophic disorders in general are associated with the metabolic syndrome. Both genetic (e.g., Berardinelli-Seip congenital lip dystrophy, Dunnigan familial partial lipodystrophy) and acquired (e.g., HIV-related lipodystrophy in patients treated with highly active antiretroviral therapy) forms of lipodystrophy may give rise to severe insulin resistance and many of the metabolic syndrome's components (Lara-Castro et al., 2007).

Body Mass Index (BMI) is an index widely used to define obesity. The World Health Organization (WHO) sets a BMI range of 18.5-24.99 kg m^-2 as normal (WHO, 2000). Although, Asians constitute a large proportion of the world's population, the majority of Asians, including the Japanese are not clearly obese according to the WHO classification, (Yoshiike et al., 1998; De Onis and Habicht, 1996) despite rapid westernization of lifestyles and a corresponding increase in metabolic risks. BMI does not always accurately indicate the degree of fatness (Smalley et al., 1990).

An increasing number of papers indicate that the degree of central fat distribution may be more closely tied to metabolic risks than BMI (Blair et al., 2001; Kaplan, 1989; Depres, 1991) Measurement of the degree of central fat distribution thus appears to be important for the early detection of subsequent health risks, even among those of normal weight. (Hsieh and Yoshinaga, 1995a; Ruderman et al., 1998; Hsieh et al., 2000).

The criteria for waist circumference proposed by WHO (midpoint between the lower border of the rib cage and the iliac crest) were based on studies of Caucasians, who generally have a higher BMI than many other ethnic groups (WHO, 2000) Also stating that obese individuals whose waist circumference (umbilical level) was 85 cm (men) or 90 cm (women) faced a higher risk of visceral fat accumulation (Japan Society for the Study of Obesity, 2000).

Several reports from Asia indicate that waist to height ratio (W/Ht) corresponds better to metabolic risk than BMI, waist circumference, waist to hip ratio or skin fold measures (Hsieh and Yoshinaga, 1995b). There are also reports that the cutoff value for W/Ht (0.5) appears to offer a simple but effective index for identifying overweight individuals and those of normal weight who face higher risks (Hsieh and Yoshinaga, 1995c; Lee et al., 1995; Hsieh and Yoshinaga, 1996; Lin et al., 2002; Victor et al., 2004).

MATERIALS AND METHODS

This is a longitudinal cross sectional study conducted on 234 patients with metabolic syndrome, for the period from the 15 of November to 30 of April, 2010. Participants for the study group were recruited from The Specialized Center for Endocrinology and Diabetes (at Al-Rusafa sector) and The National Center for Treatment and Research of Diabetes in Al-Mustanseria College of Medicine (at Al-Karkh sector) Baghdad. These two centers are the referral points for diabetic patients in Baghdad.

Patients included were diagnosed to have metabolic syndrome by specialists in both centers. Age and gender were recorded for each patient; height was calculated from the anthropometric measurements standing height measurement (CMS weighing equipment LTD, England).

The patient stood shoeless with the heels and back in contact with the vertical column of the scale. Weight measurement was done by digitalweightscale (Seca, Australia). Before each measurement the digital scale was adjusted to zero, the patient was asked to take-off his or her shoes and jackets before weighing and the weight was taken to the nearest fraction of kg (to the closest 0.1 kg).

Body Mass Index (BMI) was calculated as weight (kg) divided by height squared (2 m) and was used as the criteria for diagnosis of overweight and obesity. Participants were divided into 3 groups: normal weight (BMI <25 kg m^-2), overweight (25 kg m^-2≤BMI <30 kg m^-2) and obese (BMI≥30 kg m^-2) (Victor et al., 2004).

Standards used to collect patients indices: Waist circumference: measured on a horizontal plane 1cm above the iliac crest. The cutoff point is: >94 cm (male), 80 cm (female) (Hsieh and Yoshinaga, 1995a). Hip circumference: measure the widest circumference of the buttocks at the area of the greater trochanters.

The cutoff point of W/H ratio: >0.9 (male), >0.85 (female). The cutoff point of W/Ht ratio is: 0.5. (Hsieh et al., 2000; Lin et al., 2002; IDF, 2006). The cutoff point of BMI is 25-34.9.

Diabetes mellitus definition: Raised fasting plasma glucose :( FPG)>100 mg dL^-1 (5.6 mmol L^-1). Or previously diagnosed type 2 diabetes. If FPG >5.6 mmol L^-1 or 100 mg dL^-1, OGTT Glucose tolerance test is strongly recommended but is not necessary to define presence of the Syndrome (Chobanian et al., 2003).

Dyslipedemia: Raised triglycerides: >150 mg dL^-1 (1.7 mmol L^-1) or specific treatment for this lipid abnormality. Reduced HDL cholesterol: <40 mg dL^-1 (1.03 mmol L^-1) in males, <50 mg dL^-1 (1.29 mmol L^-1) in females or specific treatment for this lipid abnormality (Chobanian et al., 2003).

Blood pressure: Was measured and evaluated using a mercury sphygmomanometer and a standard clinical protocol according to the Joint National Committee (JNC-VII) report. After 10 min of resting, two readings of the systolic and diastolic BP separated by 5 min were averaged to the nearest 2 mmHg from the top of the mercury meniscus.

Systolic BP was recorded at the first appearance of sounds and diastolic BP at phase V at the disappearance of sounds. Hypertension was defined as systolic BP = 140 mmHg and/or diastolic BP = 90 mmHg. The validity of the weight scales and sphygmomanometers was censured by calibration prior to their use (Benner et al., 2008).

Statistical analysis: Data were analyzed using descriptive statistics (frequencies and percentages) and analytic statistics (person correlation two ways ANOVA) by SPSS, version 11.p<0.05 was considered statistically significant (Zaadstra et al., 1993).

RESULTS AND DISCUSSION

The studied sample consist of 234 with 125 male participants and 109 female, the mean age for male was 45.73 (±7.83) years while for female was 46.92 (±7.83) years. The BMI mean was nearly the same for both sexes and showed no significant difference but this difference was significant with W/H ratio 0.007 (-0.05 to -0.008) as shown in Table1.

About (91.03%) of the total sample were having Diabetes mellitus (DM) with nearly similar percentage of male and female (63.25%) of the sample were having hypertension (66.40% ) were male and (59.63%) were female, as for hyperlipedemia nearly (83% )of the sample were sulfuring from elevated serum cholesterol level ,2/3 (74.36%) were having elevated triglycerides as shown in Table 2. Most of the participants (85.74%) have no physical activity, while (49.15%) of them had family history of hypertension and diabetes mellitus.

There was a positive correlation between BMI andage, WC, HC, W/H ratio, FBS, TG and HDL, while there was a negative correlation between BMI and cholesterol, diastolic andsystolic blood presser in male participants. Similar result was obtained with female participants in except for negative correlation of BMI with TG as shown in Table 3.

A positive correlation was obtained between W/H ratio and BMI, FBS, TG and HDL, while negative correlation was found with age, cholesterol, systolic and diastolic blood presser in male participants. Similar result was obtained for female participants except for the negative correlation of W/H ratio with FBS as shown in Table 4.

Regarding the mean of BMI in both gender as cross classified DM,HT, Cholestrol, TG, HDL, PE, FH(HT/DM). Two ways ANOVA only, reviled no statistical association as shown in Table 5.

Similar result was obtained regarding the mean of W/H ratio in both gender as cross classified with cholesterol, triglicerides, high density lipoprotein, family history hypertension/Diabetes Millitus) except for Physical activity were the difference in mean is significantly associated as shown in Table 6.

Relation of W/Hip ratio and mean age: The BMI mean was nearly the same for both sexes and showed no significant difference but this difference was significant with W/H ratio. In a sample of Dutch women, a lower WHR was associated with high fecundity and was a better predictor than other variables such as body mass index (Marlowe and Wetsman, 2001).

In a second study, without the weight categories and with frontal WHR ranging from 0.4-1.0, Hadza men preferred the highest ratios of 0.9 and 1.0 Wang et al. (2005). This may be because women with a larger waist appear heavier.

 

Table 1:	Characteristics of the studied sample by sex and age
BMI: Body Mass Index, WC: Waist Circumference, HC: Hip Circumference, W/H Waist Hip ratio, FBS: Fasting Blood Sugar, TG: Triglycerides, Chol. Cholesterol, HDL: High Density Lipoprotein, SBP: Systolic Blood Pressure, DBP: Diastolic Blood Pressure

 

 

Table 2:	Associated condition (determinants) by sex
DM: Diabetes Mellitus; HT: Hypertension, Chol. Cholesterol, TG: Triglycerides; HDL: High Density Lipoprotein, Physical activity, FH: Family History

 

 

Table 3:	Corralation of BMI ratio
WC: Waist Circumference, HC: Hip Circumference, W/H: Waist Hip ratio, FBS: Fasting Blood Sugar, TG: Triglycerides, Chol. Cholesterol, HDL: High Density Llipoprotein, SBP: Systolic Blood Pressure, DBP: Diastolic Blood Pressure

 

 

Table 4:	Correlation of W/H R
BMI: Body Mass Index, FBS: Fasting Blood Sugar, TG: Triglycerides, Chol. Cholesterol, HDL: High Density Lipoprotein, SBP: Systolic Blood Pressure, DBP: Diastolic Blood Pressure

 

BMI and W/Hip ratio correlation: A positive correlation was obtained between W/H ratio and BMI, FBS, TG and HDL. Compared with Body Mass Index (BMI), anthropometric measures of abdominal obesity (e.g., Waist Circumference (WC) Waist to Hip Ratio (WHR), sagittal abdominal diameter) appear to be more strongly associated with metabolic risk factors (Despres and Lemieux, 2006) incident CVD events and death. The cardio-metabolic risk associated with abdominal obesity is attributed to the presence of Visceral Adipose Tissue (VAT) which promotes insulin resistance, dyslipidaemia and hypertension (Blair et al., 2001).

Physical activity: With Physical activity, the difference in mean was significantly associated. Two recent reviews have evaluated the relation between physical activity and CVD/cancer incidence and mortality (Haapanen-Niemi et al., 2000; Stevens et al., 2002). They conclude that individuals who report regular physical activity are less likely than sedentary individuals to die from coronary heart disease, stroke, CVD, certain cancers and all causes. Several studies have assessed the independent and combined effects of fattiness and physical fitness on mortality (Wannamethee and Shaper, 2001; Haapanen-Niemi et al., 2000).

 

Table 5:	Association of BMI (2 way ANOVA)
DM: Diabetes Mellitus; HT: Hypertension, Chol. Cholesterol; TG: Triglycerides HDL: High Density lipoprotein; Physical activity, FH: Family History

 

 

Table 6:	Association of W/HR (2 way ANOVA)
DM: Diabetes Mellitus; HT: Hypertension, Chol. Cholesterol; TG: Triglycerides; HDL: High Density Lipoprotein; Physical activity; FH: Family History

 

Moderate or high level of cardio respiratory fitness may be protective against the excess mortality among overweight and obese individuals.

CONCLUSION

WHR was significantly associated with the risk of incident CVD events. These simple measures of abdominal obesity should be incorporated into CVD risk assessments in metabolic syndrome.

How to cite this article:

Lujain Anwar Al-Khazrajy, Yossif Abdul Raheem and Yossra Khalaf Hanoon. Sex Differences in the Impact of Body Mass Index (BMI) and Waist/Hip (W/H) Ratio on Patients with Metabolic Risk Factors in Baghdad.
DOI: https://doi.org/10.36478/rjmsci.2010.298.304
URL: https://www.makhillpublications.co/view-article/1815-9346/rjmsci.2010.298.304