CORRELATION OF WAIST-HEIGHT RATIO WITH MODIFIABLE CARDIOVASCULAR RISK FACTORS
DEPARTMENT OF GENERAL MEDICINE
KAMINENI INSTITUTE OF MEDICAL SCIENCES, NARKETPALLY
CORRELATION OF WAIST-HEIGHT RATIO WITH MODIFIABLE CARDIOVASCULAR RISK FACTORS
INTRODUCTION:
> The Indian subcontinent is undergoing an epidemiological upheavel as non-communicable diseases are becoming major cause of morbidity and mortality.
> Rising incidence of diabetes mellitus, systemic hypertension,dyslipidemias and obesity,the well known risk factor for cardiovascular disease is the leading cause for increased incidence of cardiovascular diseases.
CARDIOVASCULAR DISEASE
> Cardiovascular diseases are the number one cause of death globally.
> Representing 31% of all global deaths in 2015.[1]
> Over three quarters of Cardiovascular diseases occur in low and middle income countries.
CARDIOVASCULAR RISK FACTORS
NON MODIFIABLE RISK FACTORS:
> Age
> Gender
> Family history
MODIFIABLE RISK FACTORS
> Hypertension
> Diabetes mellitus
> Obesity and overweight
> Dyslipidemia
Behavioral causes:
Excessive stress
Alcohol abuse
Tobacco use
Physical inactivity
HYPERTENSION
>
Definition of Hypertension according to National Institute of Health
and Care Excellence guidelines is Clinical Blood Pressure of
140/90mmHg or higher and subsequent ambulatory blood pressure
monitoring daytime average or home blood pressure monitoring average is
135/85 mmHg or higher[2]
> Hypertension doubles the risk of cardiovascular diseases like coronary heart disease, Congestive heart failure.
TYPE 2 DIABETES
Ø Diabetes mellitus refers to a group of common metabolic disorders that share the phenotype of hyperglycemia.[3]
Ø It predisposes to cardiovascular diseases.
Ø It is defined as per the American Diabetic Association Guidelines as:
1) Fasting plasma glucose of more than or equal to 7.0mmol/L(126 mg/dl)
2) 2hour plasma glucose of more than or equal to 11mmol/L(200mg/dl)
3) Glycosylated haemoglobin(HbA1c) more than or equal t 6.5%.
DYSLIPIDEMIA
> Dyslipidemia is a metabolic abnormality leading to a persistent increase in the plasmatic concentration of cholesterol and triglycerides.
> Dyslipidemia can be classified into an
1) Hypertriglyceridemia
2) Hypercholesterolemia
3) Mixed hyperlipidemia
> Elevated levels of lipids are well documented risk factors for cardiovascular disease.
OBESITY
Ø Worldwide obesity has nearly tripled since 1975.
Ø In 2016, more than 1.9 billion adults, 18years and old were overweight. Of these over 650 million were obese.
Ø Body mass index(BMI) is a simple index of obesity.
Ø Obesity is defined as the Body mass index greater than or equal to 30, according to WHO guidelines.
Ø Obesity is also major risk factor for Type-2 Diabetes mellitus,Cardiovascular morbidity and mortality.
Ø Not only the total amount of fat, but the distribution of fat is also important.
Ø
Evidence suggests that central fat or ‘’android distribution’’ is more
strongly related to cardiovascular risk than peripheral fat or ‘’gynoid
distribution’’.
Ø This
maybe because abdominal obesity is associated with increased secretion
of fatty acids, adipocytokines, hyperinsulinemia, hypertension and
atherogenic dyslipidemia, and leads to greater cardiovascular risk.
ØSeveral
easily obtained anthropometric measurements can predict diabetes and
other risk conditions, such as hypertension or Metabolic syndrome.
Ø Cross sectional studies have shown that the Waist-to-Height ratio(WHtR), Waist Circumference(WC), and Body mass index(BMI) are able to identify cardiovascular risk factors.
Ø Waist-to-Height Ratio and Waist circumference appears better predictors than BMI -> Because of the relation between WC and Central obesity.
ØThough BMI is widely used for assessing Overweight and obesity as it doesnot distinguish
1) Fat from muscle
2) Different fat distributions
Ø Other useful tools for detecting obesity are the waist circumference and Waist to hip ratio.
Ø Few
studies have shown that Waist to height ratio has outperformed BMI in
the detection of Impaired fasting plasma glucose(FPG), Type 2 Diabetes
mellitus, Hypertesion, Atherogenic dyslipidemia and Metabolic syndrome.
Ø Till
today, Body mass index and waist circumference are the two popular
parameters used to assess the cardiovascular risk factors.
Ø So we are still in need of simple,cheap and effective anthropometricparameter to assess the cardiovascular risk for our population.
Ø Height is an independent negative predictor of cardiovascular disease,so waist circumference,as a parameter of visceral obesity should be taken in context to height as waist/height ratio.
Ø In our study, we shall correlate waist/height ratio with modifiable cardio-metabolic risk factors.
AIM
Ø CORRELATION OF WAIST-HEIGHT RATIO WITH MODIFIABLE CARDIOVASCULAR RISK FACTORS
OBJECTIVES
Ø To correlate waist- height ratio with Hypertension
Ø To correlate waist- height ratio with Diabetes mellitus
Ø To correlate waist- height ratio with Dyslipidemia
Ø To correlate waist- height ratio with obesity.
MATERIALS
STUDY DESIGN: Cross sectional study
PLACE OF STUDY: Outpatients and Inpatients of General medicine department at Kamineni Institute Of Medical Sciences,Narketpally.
PERIOD OF STUDY: October 2017 to September 2019
INCLUSION CRITERIA
Ø Patients more than 18 years of age will be included, both the males and females.
• Patients with elevated blood pressure-Any combination of
1.Systolic blood pressure more than or equal to 140mmhg and/or,
2.Diastolic blood pressure more than or equal to 90mmhg and/or,
3.Patients with physician diagnosis of hypertension and/or,
4.Patients receiving antihypertensive medication.
• Patients with type 2 diabetes mellitus:Any combination of
1) Fasting plasma glucose more than or equal to 7mmol/L(126mg/dl) or
2) 2-hour Plasma glucose more than or equal to 11mmol/L(200mg/dl) or
3) Patients with physician diagnosis of diabetes or
4) Patients receiving anti-diabetic medication.
• Patients with Dyslipidemia-
1) Patients on Treatment for dyslipidemia or
2) Two or more abnormal serum lipid measurements including
-Total cholesterol more than equal to 270mg/dl
-LDL cholesterol more than or equal to 188mg/dl
-Triglycerides more than or equal to 150mg/dl
-HDL cholesterol less than or equal to 44mg/d
• Patients with Obesity. (BMI more than or equal to 30)
EXCLUSION CRITERIA
ØPatients who can produce falsely elevated anthropometric parameter, Waist circumference and weight due to-
1.Patients with Ascites and Volume overload.
2.Patients with Hypothyroidism.
3.Non-Modifiable risk factors like Premature Menopause.
4.Short Stature
METHODOLOGY
It includes the following:
1) Ouestionnaire Interview
2)Anthropometric measurements
3)Blood pressure recording
4)Investigations
QUESTIONNAIRE INTERVIEW
Ø A standardized questionnaire is administered to obtain information on demographics and other factors such as:
1) Age(>18 years)
2) Gender
3) Occupation
4) Medical history
5) Family history
ANTHROPOMETRIC MEASUREMENTS
Ø Measurements of the following will be taken in accurate measurement techniques:
1. Height
2. Weight
3. Waist circumference
Height and Weight
Ø Body weight and height will be measured-
1)With light clothing
2)With no shoes
3)With Calibrated scales and
4)A well mounted Stadiometer respectively.
Ø Body mas index (BMI) can be calculated from Height and weight.
BODY MASS INDEX(BMI)
ØBMI is calculated as weight divided by height squared.
Weight in Kgs
[Height in cms]²
Ø Cutoff points for Asian Indians according to WHO:
1)Underweight <18.5
2)Normal Range 18.5- 22.9
3)At risk 23-24.9
4)Overweight >25
5)Obese - >30
WAIST CIRCUMFERENCE
ØWaist
circumference will be measured half way between the lowest costal
margin and the iliac crest at the end of a normal expiration using an
inch tape.
ØAbdominal obesity according to ATP III criteria is defined as :
1)Waist circumference more than or equal to 102cm in men (or)
2)Waist circumference more than or equal to 88cm in women
ØBut for Asian Indians waist circumference is low compared Western population
ØIn Asians the cutoff values are:
1)For Males > 90cms
2)For Females > 80cms
ØIt is used in calculating the waist to height ratio.
WAIST-TO-HEIGHT RATIO (WHtR)
Ø Waist to height ratio(WHtR) is calculated by dividing Waist circumference by Height in centimeters.
Waist circimference/Height
Ø Optimal cutoffs for WHtR from few Japanese studies range from:
1) 0.51 to 0.53 in men
2) 0.48 to 0.50 in women
Ø The Cutoff used in this study for WHtR will be 0.5, above which it is abnormal.
Ø This means the Waist circumference should be kept below half of the height of the individual.
Ø If WC increases more than half of the height, the cardiovascular risk increases as per the study.
BLOOD PRESSURE MEASUREMENT
ØIn
our study blood pressure recording will be done in the following
manner- Blood pressure will be recorded three times for each individual
subject, with a gap of half an hour each using a sphygmomanometer.
INVESTIGATIONS
1.Complete blood picture
2.Complete urine examination
3.Fasting lipid profile
4.Fasting thyroid profile
5.Fasting plasma glucose
6. 2 Hour Post prandial blood sugars
7.Glycosylated hemoglobin(HbA1c)
8.Blood urea
9.Serum creatinine
10.USG abdomen and pelvis
REFERENCES
1.Freedman
DS, Kahn HS, Mei Z, et al. Relation of body mass index and
waist-to-height ratio to cardiovascular disease risk factors in children
and adolescents: the Bogalusa Heart Study. Am J Clin Nutr 2007;86:33–40. 2.Ashwell M, Gibson et al. Waist to height ratio as an indicator of early health risk: simpler and more predictive than using a ‘matrix’ based on BMI and waist circumference. BMJ Open 2016.
3. M.
Ashwell, P. Gunn and S. Gibson et al. Waist-to-height ratio is a better
screening tool than waist circumference and BMI for adult
cardiometabolic risk factors: systematic review and meta-analysis. International Association for the Study of Obesity, Obesity reviews @ 2011.
4. Adam D. Bohr, Kelly Laurson, Matthew B. McQueen et al. A novel cutoff for the waist-to-height ratio predicting metabolic syndrome in young American adults. BMC Public health, 2016.
5. Schulze MB, Heidemann C, Schienkiewitz A, Bergmann MM, Hoffmann K, Boeing H.Comparison of anthropometric characteristics in predicting the incidence of type 2 diabetes in the EPIC-Potsdam study.Diabetes care 2006;29:1921-1923
6.Gelber RP, Gaziano JM, Orav EJ, Manson JE, Kurth T.Measures of obesity and cardiovascular risk among men and women.J Am Coll Cardiol 2008;52:605-615
7. Shin Dong Hsieh MD Takashi MD et al.The Superiority of Waist/Height ratio to evaluate coronary risk factors.Preventive medicine.2005.(40).216-220
8. Klein S, Allison DB, Heymsfield SB, Kelley DE, Leibel
RL, et al. Waist circumference and cardiometabolic risk; a consensus
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Management and Obesity Prevention; NAASO, The Obesity Society; the
American Society for Nutrition; and the American Diabetes Association.
Am J Clin Nutr 2007, 85:1197-202.
9.World Health Organization WHO Definition and Diagnosis of Diabetes Mellitus and Intermediate Hyperglycemia, 1-46. Report of a WHO/IDF Consultation Available at http://www.who.int. Geneva: World Health Organization; 2006.
10. Sonmez et al.Which method should be used to determine the obesity in patients with CAD(BMI,Waist circumference).Int J Obes Metab Discord (2003) ,27(3):341 (6).
11.DL Longo, AS Fauci, DL Kasper, SL Hauser, J Jameson JL. Diabetes Mellitus:Diagnosis,classification,and pathophysiology. In: Harrison’s Principles of Internal Medicine. 19th ed. McGraw-Hill; 2015. p.2399.
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