Obesity in women – risk factors and how weight loss surgery improves survival

A fat, or triglyceride, molecule. Note the three fatty acid chains attached to the central glycerol portion of the molecule.

Over the last two decades the rates of obese and overweight women in Australia has doubled. The NHMRC conducted a survey in 2007/2008 (published 2010) revealing that 30.9% of the female Australian population were overweight (BMI 25-30 kg/m2) and 24% were obese (BMI> 30 kg/m2). The metabolic effects of excess adipose tissue contributed to ill health independent of the increased fatty tissue itself.

The role of adipose tissue is to produce various hormones (e.g. Leptin, Resisitin) and cytocines (e.g. tumor necrosis factor alpha, interleukin-6) which have the ability to interact with many organ systems. Excess adipose tissue affects these usually helpful intercellular messengers and contributes significantly to the development of chronic diseases, affecting health and well being.

Obesity affects men and women differently, with women having the higher risk for some of the diseases listed below. In addition, they have the burden of illnesses specific to obese females.

Type 2 Diabetes Mellitus (DM2)

Excess body fat is associated with 30% of DM2 in those of Asian descent, 80% of cases in those of European descent and 100% of cases in Pacific Islanders. With 280 new cases every day, DM2 is the fastest growing health problem in Australia. The risk of developing DM2 in overweight women is 3.9 times (male 2.4) higher compared to women who have normal weight. The DM2 risk for females dramatically increases to 12.4 times if obese, which is twice as high as obese males.

Pregnancy

The risk of developing DM2 is higher over the age of 45. However, younger women during their child bearing years also have a 5-10% chance of developing gestational diabetes. After other factors such as a positive family history of DM2, obesity significantly increases the risk for a pregnant woman to develop insulin resistance and gestational diabetes. This in turn is associated with an increased diabetes risk later in life.

The chance for miscarriage increases for overweight women by 1.3 and in the obese by 2.2. Maternal obesity is associated with a more than doubled risk of stillbirth and neonatal death compared with women of normal weight. Obesity triples the risk of pre-eclampsia to 10%.

Polycystic ovarian syndrome (PCOS)

Up to 15% of all women are affected by PCOS and about 70% of them are obese. Frequently, weight gain precedes the clinical features which include oligomenorrhea or amenorrhoea (70%); infertility (40% ) and hirsutism in association with hyperandrogenism (70%). PCOS is often associated with hyperinsulinism which may lead on to metabolic syndrome.

Cardiovascular diseases

The risk of developing hypertension, cardiovascular disease, stroke or pulmonary embolism increases in overweight women and further deteriorates when becoming obese. The leading pathology is pulmonary embolism.

Cancer

The chances of developing colorectal cancer is increased in overweight and obese women. Renal cancer may occur more frequently in overweight women than men and increases the risk in obese women by 2.6 (men 1.8).

Obesity only slightly increases the risk of breast cancer. However, endometrial cancer occurs more frequently in overweight women with a doubling of the risk if obese.

		Overweight -risk	Obese - risk
Cardiovascular	Hypertension	1.6	2.4
	Coronary Artery Disease	1.8	3.1
	Congestive Heart Failure	1.3	1.8
	Pulmonary Embolism	1.9	3.5
	Stroke	1.2	1.5
Cancer	Breast, Postmenopausal	1.1	1.1
	Colorectal	1.5	1.7
	Endometrial	1.5	3.2
	Kidney	1.8	2.6

Mental Health

Depression is a major health problem for obese women. A dysmorphic body image frequently mediates the relationship between obesity and psychological distress. Chronic tiredness from sleep apnoea and decreased physical ability also contributes to the development of depression. The majority of women (57%) with major to severe depression are obese.

Survival

These combined risk factors lead to a shorter life expectancy in overweight and obese women. At the age 40 years staying overweight reduces the life expectance by 3.3 years and in smokers by 6.2 years. Obesity further significantly reduces the life expectancy by 7.1 years and in smokers by 13.3 years.

	Overweight	Obese
	Female 40 y	Female 40y
Non-smoker	-3.3y	-7.1y
Smoker	-6.2y	-13.3y

How to treat obesity?

Diet and exercise are the preferred methods for losing weight. However, after repeated failures bariatric surgery is an option for the morbidly obese.

Controlled studies have shown that after 10 years individuals who received non-surgical treatment for obesity gain 1.6% of their total body weight and patients who received bariatric surgery lose 16%. Women who received a gastric bypass were the most successful with a total weight loss of 25% of their total body weight.

After 15 years of follow up, the women in the surgical cohort had a significantly smaller cancer incidence compared to the women who remained obese. The same study also reported better sleep, increased activity and less depression in the surgical patients.

Bariatric surgery has long term benefits for patients with the metabolic syndrome. Newer procedures such as the Omega Loop and Mini gastric bypass are more effective (90%) than the older gastric sleeve or gastric bypass surgery (50%) for drug free management of DM2, hypertension and hyperlipidaemia.

The Royal College of Obstetricians and Gynaecologist has recently recommended bariatric surgery for obese women with PCOS since the endocrine problems inhibiting ovulation and pregnancy significantly improve.

For the right patient bariatric surgery is able to maintain long term weight loss and result in a longer, healthier and happier life.

References:

Details: Written by: Assoc Prof Harald Puhalla, MD, FRACS, (Sponsored Article); Published: 07 December 2015

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