Obesity and metabolic syndrome Flashcards
- Define obesity using BMI and waist circumference.
BMI is determined by weight in kilograms divided by height in meters squared (BMI = kg/m2).
overweight 25.0 to 29.9 kg/m2,
obesity 30 kg/m2 or greater
Severe obesity 40 kg/m2 or greater
elevated waist circumference definitions-
≥ 35 inches for women, ≥ 40 inches for men
The reason to measure waist circumference is that excess abdominal fat is associated with greater risk than fat located in other areas (buttocks, thighs). Abdominal fat is associated with fat deposition in internal organs (visceral fat). Thus, abdominal obesity is an independent risk factor for cardiovascular disease, type 2 diabetes, hypertension, hypercholesterolemia and even mortality, even when BMI is not elevated. Measurements of waist circumference can provide useful information about health risk, especially for adults with an intermediate BMI of 25-35 kg/m2.
- List the possible causes of obesity.
Obesity caused by long term positive energy balance
- Define Metabolic Syndrome using the current AHA/NCEP definition.
Greater than 3 of the following factors:
Waist circumference >40 men >35 women
TG’s >/=150
HDL130
Fasting glucose >/= 110
- List the steps in the clinical evaluation of the obese patient.
History- cronology of bodyweight, attempts at weight loss, related medical conditions, meds that could cause wt gain, smoking and etoh history, fh, diet and physical activity, depression screen, goals for wt loss
Physical- Ht, Wt, BP, O2 Sat, pulse, BMI, waist circumference, signs of pulm HTN, venous insufficiency, (skin hyperpigmentation, edema, rhales), sign of thyroid disease, signs of insulin resistance and diabetes (acnthosis nigricans
Lab tests- lipid panel, A1C, glucose, liver enzymes, others under clinical suspicion
- List the health problems that are associated with obesity.
DM2, Dyslipidemia, CAD, sleep apnea, non-alcoholic fatty liver disease
Type 2 Diabetes and Impaired Glucose Tolerance:
BMI, abdominal fat distribution and weight gain are important risk factors for the development of type 2 diabetes. Data from NHANES III found that almost 70% of adult men and women in the U.S. with type 2 diabetes have a BMI of 27 or greater, and the risk of diabetes increases linearly with BMI. Data from 8 years of follow up of a cohort of over 113,000 US women aged 30-55 in the Nurses’ Health Study found that, among women of BMI 23-23.9 kg/m2, the relative risk of diabetes was 3.6 times that of women having a body mass index less than 22 kg/m2.
Dyslipidemia: Visceral obesity is associated with elevated triglycerides, low HDL cholesterol, and increased small, dense LDL particles. Data from NHANES III suggest that prevalence of hypercholesterolemia (total cholesterol > 240 mg/dl) increased progressively with BMI in men. In women, the prevalence was highest at a BMI of 25-27 kg/m2, and did not increase further with increasing BMI.
Coronary Artery Disease (CAD). Obese persons, particularly those with abdominal fat distribution, are at increased risk for CAD. The risk of CAD begins to increase at a BMI of 23 kg/m2 for men and 22 kg/m2 for women. It was previously thought that most of the increased risk was mediated by obesity related increases in risk factors, particularly hypertension, dyslipidemia, impaired glucose tolerance/diabetes, and the metabolic syndrome. However, several long term epidemiologic studies including the Nurses’ Health Study and the Framingham Study have shown that overweight and obesity increased the risk for CAD even after correction for other known risk factors. The American Heart Association has added obesity to its list of major risk factors for CAD.
Sleep Apnea: Obese men and women are also at high risk for sleep apnea, in which partial or complete upper airway obstruction during sleep leads to episodes of apnea or hypopnea. The interruption in nighttime sleep and repeated episodes of hypoxemia lead to daytime somnolence, morning headache, systemic hypertension, and can eventually result in pulmonary hypertension and right heart failure. In a study of two hundred obese women and 50 obese men (mean BMI 45.3 kg/m2) and 128 controls matched for age and sex, 40% of obese men and 3% of obese women demonstrated sleep apnea warranting therapeutic intervention. Another 8% of men and 5.5% of women showed apneic activity that warranted recommendation for evaluation in the sleep laboratory. In contrast, none of the 128 controls demonstrated sleep apneic activity severe enough for therapeutic intervention.
Non-Alcoholic Fatty Liver Disease: Obesity is associated with a spectrum of liver disease known as non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH). Manifestations of this disorder include hepatomegaly, abnormal liver associated enzyme tests, and abnormal liver histology including macrovesicular steatosis, steatohepatitis, fibrosis, and in a worst case scenario, cirrhosis. NAFLD/NASH has become a common cause of cirrhosis in the U.S., along with viral hepatitis and alcohol use. The exact prevalence of NAFLD/NASH in obese patients is not fully known. However data, from autopsy studies suggest that steatohepatitis occurs in approximately 20% of obese patients.
Waist circumference should be measured: Over the umbilicus Over the superior margin of the iliac crests Over the inferior margins of the ribs Where the patient wears their belt Over the posterior superior iliac spine
Over the superior margin of the iliac crests
Which statement is the most accurate about body mass index (BMI) and waist circumference (WC) in predicting the risk of health complications?
WC is more accurate than BMI
BMI is more accurate than WC
BMI and WC are equal in predicting risk
WC predicts risk, but only if BMI is elevated
BMI and WC both have value independently in predicting risk
BMI and WC both have value independently in predicting risk
Criteria for the metabolic syndrome include all of the following except:
Elevated low density lipoprotein (LDL) cholesterol
Low high density lipoprotein (HDL) cholesterol
Elevated fasting glucose
Elevated blood pressure
Abdominal obesity (elevated waist circumference)
Elevated low density lipoprotein (LDL) cholesterol
All of the conditions below are associated with obesity except
Type 2 diabetes Obstructive sleep apnea Appendicitis Polycystic ovarian syndrome Cancer
Appendicitis
Routine laboratory evaluation of a patient with obesity should include all of the following except Hemoglobin A1c Fasting lipid panel Liver associated enzymes Cortisol level TSH
Cortisol level
According to measured values (NHANES data), the prevalence of obesity and overweight among adults ages 20 and over in the United States are: Obesity 20%, Overweight 18% Obesity 24%, Overweight 20% Obesity 30%, Overweight 26% Obesity 35%, Overweight 33.5% Obesity 38%, Overweight 40%
Obesity 35%, Overweight 33.5%
