Polycystic Ovary Syndrome and Overweight: What the Relationship Implies about the Cause of Weight Gain

Polycystic ovary syndrome ("POS" or "PCOS") often coexists with obesity and overweight. But why? And what can this association tell us about the nature of obesity?

The Caloric Balance Hypothesis says PCOS leads to overweight because the condition either drives appetite and/or suppresses metabolism. (After all, if "calories count," then in order for any disease to cause weight gain, it must do so by acting on caloric balance.)

The Lipophilia Hypothesis tells us that a high carbohydrate diet and/or chronic hyperinsulinemia can drive both POS and obesity. So the root cause of both overweight and this syndrome is the same.

So which of these theories makes more sense?

1. Here is an article from the New England Journal of Medicine: "Polycystic ovary syndrome."[1]

The authors note that, back in 1935 when POS was first identified, researchers catalogued the condition thusly: "women with amenorrhea, hirsutism, obesity, and a characteristic polycystic appearance to their ovaries."

2. "Obesity in the polycystic ovary syndrome."[2]

These authors note that "approximately 50% of POS women are overweight or obese... obesity may play a pathogenic role in the development of the syndrome in susceptible individuals."

They also say "obesity ... may be partially responsible for insulin resistance and associated hyperinsulinemia in women with PCOS."

3. Here is another curious article: "Profound peripheral insulin resistance, independent of obesity and polycystic ovary syndrome."[3]

The authors note that: "controversy exists as to whether insulin resistance results from PCOS or from the obesity that is frequently associated with it."

The authors tested this proposition and found that "PCOS women have significant insulin resistance that is independent of obesity, changes in body composition, and impairment of glucose tolerance."

So insulin resistance resulted "independent of obesity." This seems to shred the Caloric Balance explanation to pieces. Because if Caloric Balance could possibly explain weight gain in PCOS patients, it would have to do so by saying that:

A) Somehow positive calorie balance drives us to accumulate more fat;

B) This, in turn, then drives conditions like PCOS.

But these authors tell us that insulin resistance exists independent of obesity, so you can't blame excess calories. And if you can't blame excess calories, the alternative explanation must be correct – namely that the fundamental cause of PCOS must be hyperinsulinemia.

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1. David A. Ehrmann, M.D. Polycystic Ovary Syndrome nejm. Volume 352:1223-1236 March 24, 2005 Number 12.

2. K.Hoeger. "Obesity in the polycystic ovary syndrome." Obstetrics and Gynecology Clinics of North America, Volume 28, Issue 1, Pages 85-97.

3. Dunaif A, Segal KR, Futterweit W, Dobrjansky A. "Profound peripheral insulin resistance, independent of obesity and polycystc ovary syndrome." Diabetes. 1989 Sep;38(9):1165-74.

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