To the Editor:
We reviewed the manuscript by Nybacka et al. (1) with great interest. The authors randomized overweight/obese women with polycystic ovary syndrome (PCOS) to investigate the effects of different lifestyle modification approaches on ovarian function and endocrine/metabolic parameters. The patients were assigned to diet, exercise or diet plus exercise for 4 months, and at least 1-year after the termination of the programs were invited to participate in a follow-up visit. A total of 14, 17 and 12 women completed, respectively, the diet, exercise and diet plus exercise intervention after 4 months, and 7 of each group completed the follow-up visit. At the end of the study the authors’ conclusion was that “properly managed diet and exercise, alone or in combination, are equally effective in improving reproductive function in overweight/obese women with PCOS, despite the minor weight loss associated with exercise.”
Corroborating with the authors, to our knowledge this is the ﬁrst report using a randomized design to compare the inﬂuence of individualized dietary and exercise intervention with professional support, and a long-term follow-up. In fact, this topic is extremely relevant in the current clinical management of PCOS because lifestyle modification is recommended as the first-line therapy for overweight/obese PCOS patients (2).
In this sense, as exercise is a crucial component of lifestyle modification, we would like to discuss the methodological procedures related to exercise intervention used by Nybacka et al. (1). The authors described that the exercise program was individually adjusted and designed to enhance the type (endurance, aerobic, and/or weight training) conforming the patient’s capacity, goals, and interest at the beginning of this intervention. However, there was no description of the basic variables of exercise training such as type, intensity, duration, frequency and progression. This definition is fundamental because the effects of exercise depend of the organization and manipulation of these basic variables (3). Additionally, the long-term effects promoted by aerobic and resistance exercise are different (4). Moreover, the detailed description of exercise intervention may facilitate its reproduction in clinical practice.
For example, Thomson et al. (5) evaluated the effects of aerobic and aerobic/resistance exercise plus an energy-restricted, high-protein diet on metabolic risk factors and reproductive function in overweight/obese PCOS women. The authors detailed both interventions with regard to basic variables of training. At the end of the study, it was possible to conclude that all interventions improved equally the cardiometabolic risk profile and reproductive function. However, the addition of aerobic or combined aerobic/resistance exercise to diet had better results on the body composition.
Therefore, for a better analysis of the clinical effectiveness and feasibility of the exercise intervention used in lifestyle modification programs designed for PCOS women, we believe that a detailed description of the exercise prescription with regard to the basic variables (i.e., type, intensity, duration, frequency and progression) is crucial.
Eduardo Caldas Costa, Ph.D.a,b
George Dantas de Azevedo, M.D., Ph.D.b,c
aDepartament of Physical Education
bPost-Graduate Program in Health Sciences
cDepartament of Morphology, Biosciences Center
Federal University of Rio Grande do Norte
1. Nybacka A, Carlström K, Ståhle A, Nyrén S, Hellström PM, Hirschberg AL. Randomized comparison of the influence of dietary management and/or physical exercise on ovarian function and metabolic parameters in overweight women with polycystic ovary syndrome. Fertil Steril. 2011 (in press).
2. Wild RA, Carmina E, Diamanti-Kandarakis E, Dokras A, Escobar-Morreale HF, Futterweit W, et al. Assessment of cardiovascular risk and prevention of cardiovascular disease in women with the polycystic ovary syndrome: a position statement by the Androgen Excess and Polycystic Ovary Syndrome (AE-PCOS) Society. J Clin Endocrinol Metab. 2010; 95(5):2038-49.
3. Garber CE, Blissmer B, Deschenes MR, Franklin BA, Lamonte MJ, Lee IM, et al. American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Med Sci Sports Exerc. 2011; 43(7):1334-59.
4. Williams MA, Haskell WL, Ades PA, Amsterdam EA, Bittner V, Franklin BA, et al. Resistance exercise in individuals with and without cardiovascular disease: 2007 update: a scientific statement from the American Heart Association Council on Clinical Cardiology and Council on Nutrition, Physical Activity, and Metabolism. Circulation. 2007; 116(5):572-84.
5. Thomson RL, Buckley JD, Noakes M, Clifton PM, Norman RJ, Brinkworth GD. The effect of a hypocaloric diet with and without exercise training on body composition, cardiometabolic risk profile, and reproductive function in overweight and obese women with polycystic ovary syndrome. J Clin Endocrinol Metab. 2008; 93(9):3373-80.
Published online in Fertility and Sterility doi:10.1016/j.fertnstert.2011.11.037
The Authors Respond:
We were pleased to read the supportive letter by Costa and Azevedo to our findings of individually adapted programs of dietary management and/or physical exercise applicable in polycystic ovary syndrome (PCOS). The fact that exercise and diet were equally effective to improve reproductive function independently of weight loss, speaks in favor of a common mechanism induced by both diet and exercise. Our preliminary data support that the underlying mechanism involves enhanced insulin sensitivity. In an extension to our study we are investigating this further.
The authors request a more detailed description of the exercise intervention used in our study in order to better evaluate its clinical effectiveness and feasibility in PCOS women. At baseline, most women estimated their level of physical activity as low corresponding to less than two hours of walking or light physical exercise a week. The exercise program, which was supervised by a physiotherapist, was based on each individual’s condition, interest and experience and aimed at increasing their physical activity to a moderate level. The exercise included walking (with or without poles), aerobics, jogging, swimming, strength training etc. with an exertion of moderate to vigorous, performed two to three times a week with a duration of 45-60 minutes each time during the intervention period. This exercise program caused only minor weight loss but improved body composition with a significant reduction of upper body fat and maintained lean body mass.
We believe that structured lifestyle management adapted to the individual’s capacity and needs and with long-term support are the most important prerequisites for successful and sustained improvement of reproductive and metabolic health in women with PCOS.
Åsa Nybacka, B.Sc.a,b
Kjell Carlström, Ph.D.a
Agneta Ståhle, Ph.D.c
Sven Nyrén, M.D., Ph.D.d
Per Hellström, M.D., Ph.D.e
Angelica Lindén Hirschberg, M.D., Ph.D.a
a Division of Obstetrics and Gynecology, Department of Women’s and Children’s Health, Karolinska Institutet and Karolinska
University Hospital, Stockholm
b Department of Clinical Nutrition and Dietetics, Karolinska University Hospital, Stockholm
c Division of Physiotherapy, Department of Neurobiology, Care Sciences, and Society, Karolinska Institutet, Stockholm
d Department of Radiology, Karolinska University Hospital, Stockholm
e Department of Medical Sciences, Uppsala University, Uppsala,
Published online in Fertility and Sterility doi:10.1016/j.fertnstert.2011.11.039