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Complications of Obesity

Dr. Shahrzad ShahidiProfessor of Nephrology

Isfahan University of Medical Sciences

Mortality & MorbidityAssociated with Obesity

The effects of excess weight on mortality &morbidity have been recognized for more than2,000 years.

It was Hippocrates who recognized that “suddendeath” is more common in those who are naturallyfat than in the lean.

Endocrinol Metab Clin N Am. 2003; 32: 761-786.

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MortalityExcess Body Weight

Mortality associated with excess body weightincreases as the degree of obesity & overweightincreases.

It is estimated that 280,000 to 325,000 deaths ayear can be attributed to obesity in the US, > 80%of these deaths occur among individuals with aBMI > 30 kg/m2.

Endocrinol Metab Clin N Am. 2003; 32: 761-786.

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Regional fat distribution can contribute to mortality. This was first noted in the beginning of the 20th century. Obese individuals with an android (or apple) distribution of

body fat are at a greater risk for diabetes & heart diseasethan were those with a gynoid distribution (pear).

Android fat distribution results in higher free fatty acidlevels, higher glucose & insulin levels & reduced HDLlevels. It also results in higher BP & inflammatory markers.

MortalityRegional Fat Distribution

Android Gynoid

Endocrinol Metab Clin N Am. 2003; 32: 761-786.

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MorbidityAssociated with Obesity

Overweight affects several diseases,although its degree of contributionvaries from one disease to another.

Additionally, the risk of developing adisease often differs by ethnic group, &by gender within a given ethnic group.

Endocrinol Metab Clin N Am. 2003; 32: 761-786.

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Cardiovascular disorders Obstructive sleep apnea Gastrointestinal disorders Metabolic disorders Cancers Psychological disorders

Complications of pregnancy Menstrual irregularities Low back pain Osteoarthritis Gout Carpal tunnel syndrome

MorbidityAssociated with Obesity

CDC

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Cardiovascular DisordersAssociated with Obesity

HypertensionStroke

Heart DiseaseVenous thrombosis 9

Hypertension HTN is identified when a BP is sustained at

≥140/90 mmHg. High BP is referred to as the “silent killer”

since there are usually no symptoms withHTN.

Some individuals find out that they havehigh BP when they have trouble with theirheart, brain, or kidneys.

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HypertensionThe Dangers

Heart failure, heart attack Brain aneurysms, stroke Kidney failure Vision changes that can result in blindness Peripheral vascular disease

Failure to find and treat HTN is serious, as untreated HTN can cause:

NHLBI11

Adapted from:http://www.obesityinamerica.org/trends.html

HypertensionPrevalence in the Overweight

0

5

10

15

20

25

30

35

Males Females

BMI < 25BMI > 25 & < 27BMI > 27 & <30

Prev

alen

ce o

f H

TN

Age-adjusted prevalenceof hypertension in

overweight U.S. adults

14.9

22.1

27.0

15.2

27.7

32.7

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Stroke

Sudden numbness or weakness, especially on one side of the body Sudden confusion or trouble speaking or understanding speech Sudden trouble seeing in one or both eyes Sudden trouble with walking, dizziness, or loss of balance or coordination Sudden severe headache with no known cause

The symptoms of a stroke include:

NINDS13

Stroke With increasing BMI, the risk of ischemic stroke

increases progressively & is doubled in those with aBMI > 30 kg/m2 when compared to those having aBMI of < 25 kg/m2.

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Cardiovascular DisordersAssociated with Obesity

Heart disease: CAD

Heart failure

Myocardial steatosis

ECG findings

AF

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Coronary Artery Disease Obesity is associated with an increased risk for CAD. Abdominal fat distribution is believed to be related as well. Data from the Nurses Health Study illustrated that women in the lowest BMI but highest

waist-to-hip circumference ratio had a greater risk of heart attack than those in thehighest BMI but lowest waist-to-hip circumference ratio.

Regional fat distribution appears to have a greater effect on CAD risk than BMI alone.

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Gastrointestinal DisordersAssociated with Obesity

Hepatobiliary DiseaseGERD/Erosive esophagitis

GI cancer

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Gallbladder Disease Cholelithiasis is the primary hepatobiliary pathology

associated with overweight. Normally, a balance of bile salts, lecithin, & cholesterol keep

gallstones from forming. If there are abnormally high levels of bile salts or, more

commonly, cholesterol, then stones can form.

J La State Med Soc .2005; 156 (1): S42-49.18

GallstonesFindings Related to Obesity

More cholesterol is produced at higher body fat levels. Approximately 20 mg of additional cholesterol is synthesized for each

kg of extra body fat. High cholesterol concentrations relative to bile acids & phospholipids

in bile increase the likelihood of precipitation of cholesterolgallstones in the gallbladder.

Endocrinol Metab Clin N Am. 2003; 32: 761-786.

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GallstonesFindings Related to Obesity

In the Nurses’ Health Study, when compared to those having a BMI of 24or less, Women with a BMI > 30 kg/m2 had a 2-fold increased risk for

symptomatic gallstones. Women with a BMI > 45 kg/m2 had a 7-fold increased risk for

symptomatic gallstones.

The relative increased risk of symptomatic gallstone development withincreasing BMI appears to be less for men than for women.

J La State Med Soc .2005; 157 (1): S42-49.20

Liver Disease Nonalcoholic fatty liver disease (NAFLD) is the

term given to describe a collection of liverabnormalities that are associated with obesity.

In a cross-sectional analysis of liver biopsies ofobese patients, it was found that the prevalenceof steatosis, steatohepatitis, & cirrhosis wereapproximately 75%, 20%, & 2% respectively.

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Liver DiseaseFatty Liver

A gradual weight reduction can helpto reduce the enlargement of the liverdue to fat, and it can normalize theassociated liver test abnormalities.

The American Liver Foundation22

Metabolic DisordersAssociated with Obesity

Diabetes MellitusDyslipidemia

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Diabetes Mellitus

Type 2 DM is strongly associated with overweight & obesity in bothgenders & in all ethnic groups.

The risk for Type 2 DM increases with the degree & duration ofoverweight in individuals.

The risk for Type 2 DM also increases in individuals with a morecentral distribution of body fat (abdominal).

J La State Med Soc .2005; 157 (1): S42-49.24

Diabetes MellitusFindings Related to Obesity

The Nurses’ Health Study demonstrated the curvilinear relationshipbetween increasing BMI and the risk of diabetes in women: Women with a BMI below 22 kg/m2 had the lowest risk of DM At a BMI of 35 kg/m2, the relative risk of DM increased 40-fold or 4,000%

The Health Professionals Follow-up Study demonstrated a similarrelationship between increasing BMI and the risk of diabetes inmen: Men with a BMI below 24 kg/m2 had the lowest risk of DM At a BMI of 35 kg/m2, the relative risk of DM increased 60-fold or 6,000%

J La State Med Soc .2005; 157 (1): S42-49.25

Diabetes MellitusFindings Relating to Weightloss

Weight loss reduces the risk of developing DM.

In the Health Professionals Follow-up Study, aweight loss of 5-11 kg decreased the relative riskfor developing diabetes by nearly 50%.

Type 2 DM was almost nonexistent with a weightloss of more than 20 kg or in those with a BMIbelow 20.

J La State Med Soc .2005; 157 (1): S42-49.26

DyslipidemiaFindings Related to Obesity

An inverse relationship between HDL cholesterol & BMI has beennoted.

This relationship may be more important than the relationshipbetween BMI & TG levels.

Low level of HDL carries more relative risk for developing heartdisease than do elevated triglyceride levels.

Central fat distribution also plays an important role in lipidabnormalities.

Endocrinol Metab Clin N Am. 2003; 32: 761-786.

HDL

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Obstructive sleep apneaOsteoarthritis

CancersComplications of pregnancy

Menstrual irregularitiesPsychological disorders (Depression, Dementia)

Other DisordersAssociated with Obesity

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Obstructive Sleep Apnea Obstructive sleep apnea is caused by repetitive upper airway obstruction

during sleep as a result of narrowing of the respiratory passages. Patients having the disorder are most often overweight with associated

peripharyngeal infiltration of fat and/or increased size of the soft palateand tongue.

American Academy of Family Physicians29

Obstructive Sleep Apnea Common complaints are loud snoring, disrupted sleep,

& excessive daytime sleepiness. Individuals with sleep apnea suffer from fragmented

sleep & may develop cardiovascular abnormalitiesbecause of the repetitive cycles of snoring, airwaycollapse, & arousal.

Because many individuals are not aware of heavysnoring & nocturnal arousals, obstructive sleep apneamay remain undiagnosed.

American Academy of Family Physicians30

Obstructive Sleep ApneaFindings Relating to Obesity

Obstructive sleep apnea affects around 4% of middle-agedadults.

Individuals having a BMI of at least 30 are at greatest riskfor sleep apnea.

Weight loss has been shown to improve the symptomsrelating to sleep apnea.

J La State Med Soc .2005; 157 (1): S42-49.31

Osteoarthritis

OA is the most common type of arthritis. 40 million Americans currently have osteoarthritis. It is a degenerative disease which frequently leads to

chronic pain and disability. For individuals > 65, it is the most disabling disease. Currently, only the symptoms of OA can be treated; there is

no cure.

NSLS32

OsteoarthritisFindings Relating to Obesity

The incidence of OA is significantly increased inoverweight individuals.

OA that develops in the knees and ankles isprobably directly related to the trauma associatedwith the degree of excess body weight.

Areas of the bodymost commonlyaffected by OA33

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CancerFindings Relating to Obesity

Associations for only 11 cancers(oesophageal adenocarcinoma, multiplemyeloma, & cancers of the gastric cardia,colon, rectum, biliary tract system,pancreas, breast, endometrium, ovary, &kidney) were supported bystrongevidence.

Kyrgiou M, et al. BMJ 2017;356

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CancerFindings Relating to Obesity

Obesity & physical inactivity may accountfor 20% of several major cancers.

J La State Med Soc .2005; 157 (1): S42-49.36

Endocrine Changes Changes in the reproductive system are among the most

common. Irregular menses & frequent anovular cycles are common. Rates of fertility may also be reduced. Disorders of sexual arousal & orgasm in women. Erectile dysfunction in men.

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Psychological DisordersAssociations with Obesity

Obesity is associated with an impaired qualityof life.

Higher BMI values are associated withgreater adverse effects.

When compared to obese men, obesewomen appear to be at a greater risk forpsychological dysfunction.

This may be due to the societal pressure onwomen to be thin.

Endocrinol Metab Clin N Am. 2003; 32: 761-786.

J La State Med Soc .2005; 157 (1): S42-49.38

Psychological DisordersWeight Loss

Intentional weight loss has been consistently associated withimproved quality of life.

Severely obese patients who lost 43 kg through gastric bypassdemonstrated improved quality of life scores to such an extent thattheir post-weight loss scores were equal to or even better thanpopulation norms.

J La State Med Soc .2005; 157 (1): S42-49.

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Other DisordersAssociated with Obesity

InfectionSkin changes

(steriae, Akanthosis nigricans,Hirsutism)Gout

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References CDC: Overweight and Obesity -- Contributing Factors. Available at:

http://www.cdc.gov/nccdphp/dnpa/obesity/contributing_factors.htm Bellanger T, Bray G. Obesity related morbidity and mortality.

J La State Med Soc. 2005; 156(1): S42-49. Bray G. Risks of obesity. Endocrinol Metab Clin N Am. 2003; 32: 787-804. National Heart, Lung, and Blood Institute (NHLBI). High Blood Pressure.

Available at: http://www.nhlbi.nih.gov/health/dci/Diseases/Hbp/HBP_WhatIs.html Obesity in America. Obesity Trends. Available at:

http://www.obesityinamerica.org/trends.html

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References National Institute of Neurological Disorders and Stroke. NINDS Stroke Information Page.

Available at: http://www.ninds.nih.gov/disorders/stroke/stroke.htm National Heart, Lung, and Blood Institute (NHLBI). What is Coronary Artery Disease?

Available at: http://www.nhlbi.nih.gov/health/dci/Diseases/Cad/CAD_WhatIs.html American Cancer Society (ACS). What is Colorectal Cancer? Available at:

http://www.cancer.org/docroot/CRI/content/CRI_2_4_1x_What_Is_Colon_and_Rectum_Cancer.asp?rnav=cri

National Cancer Institute (NCI). Obesity and Cancer. Available at:http://www.cancer.gov/cancertopics/factsheet/Risk/obesity

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References American Liver Foundation. Diet and Your Liver. Available at:

http://www.liverfoundation.org/cgi-bin/dbs/articles.cgi?db=articles&uid=default&ID=1022&view_records=1

Mayo Clinic. Your Liver: An Owner’s Guide. Available at:http://www.mayoclinic.com/health/liver/DG00038

American Academy of Family Physicians (AAFP). Obstructive Sleep Apnea.Available at: http://www.aafp.org/afp/991115ap/2279.html

National Synchrotron Light Source (NSLS). Osteoarthritis. Available at:http://www.nsls.bnl.gov/about/everyday/osteoarthritis.html

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