[Joan_Gandy]_Manual_of_Dietetic_Practice(b-ok.xyz)(2).pdf

3.1 Women’s health 3.1.1 Polycystic ovary syndrome Yvonne Jeannes SECTION...

3.1 Women’s health 3.1.1 Polycystic ovary syndrome Yvonne Jeannes SECTION 3 Key points  Polycystic ovary syndrome (PCOS) presents as a range of symptoms that vary in severity.  Weight management should be the primary therapy in overweight women with PCOS.  Dietary modification should aim to improve insulin resistance.  A patient centred approach is needed to improve symptoms as well as reduce the risk of developing diabetes and cardiovascular disease.  Binge eating behaviour is common in PCOS. Polycystic ovary syndrome (PCOS) is a heterogeneous cially obesity (Pasquali et al., 2011). Hyperandrogenism condition and women may present with one or several of is present in 60–80% of women, either clinically (hir- the following symptoms: menstrual irregularity and fertil- sutism, male pattern alopecia, acne) or biochemically ity problems, excess male pattern hair (hirsutism), male (elevated total or free testosterone) (Azziz et al., 2006). pattern alopecia, acne, central adiposity, insulin resist- Although insulin resistance is not among the diagnostic ance and depression (Azziz et al., 2006; Dokras et al., criteria for PCOS, most women with PCOS, both the lean 2011). Symptoms vary in severity and can change over the and overweight, have a form of insulin resistance intrinsic lifecycle; PCOS often becomes clinically apparent during to PCOS (Baptiste et al., 2010). Hyperinsulinaemia pro- adolescence (Ojaniemi et al., 2010). The diagnostic crite- motes ovarian hyperandrogenism and reduces hepatic ria for PCOS involve the presence of two of the following production of sex hormone binding globulin (SHBG), features and exclusion of other endocrine disorders thus increasing free testosterone levels. Together hyper- (ESHRE and ASRM, 2004): insulinaemia and hyperandrogenaemia disrupt follicle growth, which leads to menstrual irregularity, anovulatory Oligo-ovulation leading to oligomenorrhoea (fewer subfertility and accumulation of immature follicles than nine menses per year), or anovulation leading to (Goodarzi et al., 2011). amenorrhoea. Hyperandrogenism – clinically (hirsutism, male pattern alopecia, acne) or biochemically. Disease consequences Polycystic ovaries. It is the most common endocrine disorder in women of It is important to note that women can be diagnosed reproductive age, affecting up to 10% (March et al., with PCOS from the presence of oligo-ovulation and clini- 2010). South Asian women have the highest prevalence cal signs of hyperandrogenism without polycystic ovaries. (Rodin et al., 1998) followed by Black women (Azziz A woman with polycystic ovaries without the other symp- et al., 2004). Between 30% and 70% of women with PCOS toms should not be diagnosed with PCOS. are obese (Barr et al., 2011) and frequently exhibit central The aetiology of PCOS is complex, with a genetic herit- obesity (Amato et al., 2011; Cascella et al., 2008) that is ability that is enhanced by environmental factors, espe- linked to greater insulin resistance (Barber et al., 2006). Manual of Dietetic Practice, Fifth Edition. Edited by Joan Gandy. © 2014 The British Dietetic Association. Published 2014 by John Wiley & Sons, Ltd. Companion Website: www.manualofdieteticpractice.com  76 Section 3: Nutrition in specific groups Obese women with PCOS are generally more sympto- Nutritional assessment matic and are at greater health risk compared with lean women with PCOS (Majumdar & Singh, 2009). Up to 50% Anthropometric measurements include determining body of women with PCOS develop impaired glucose tolerance mass index (BMI) and waist circumference to inform risk or type 2 diabetes by the age of 40 years (Ehrmann et al., of comorbidities and dietary management. A dietary 1999) and there is a greater incidence of gestational dia- assessment to determine habitual dietary habits should betes (Bals-Pratsch et al., 2011) (see Chapter 7.12). South also aim to detect any binge eating behaviour (see Chapter Asian patients tend to exhibit greater insulin resistance 7.10.1). Due to the increased prevalence of impaired and are at an increased risk of type 2 diabetes (Wijeyaratne glucose tolerance and type 2 diabetes in PCOS, an oral et al., 2002). Up to 47% of women with PCOS exhibit glucose tolerance test may be performed, and due to the features of the metabolic syndrome (Ehrmann et al., increased prevalence of cardiovascular risk factors, meas- 2006). Women with PCOS have a greater prevalence of urements of blood pressure, plasma total, low density cardiovascular disease (CVD) risk factors, including lipoprotein (LDL) and HDL cholesterol as well as triglyc- hypertriglyceridaemia, low high density lipoprotein erides are recommended (Wild et al., 2010). (HDL) cholesterol, hypertension and endothelial dysfunc- tion (Wild et al., 2010). They are also more likely to Nutritional management develop cancer of the endometrium (Chittenden et al., SECTION 3 2009; Fearnley et al., 2010). Weight loss through dietary restriction and increased The symptoms associated with PCOS have been shown physical activity are key management strategies for over- to lead to a reduction in health related quality of life weight and obese women with PCOS (Moran et al., 2009). (Jones et al., 2008). Depression and anxiety are common The optimal method of achieving sustainable weight loss in PCOS (Dokras et al., 2011). Studies have indicated a is under constant debate; the aforementioned studies higher prevalence of eating disorders in women with demonstrating clinical benefit of weight loss in women PCOS (Morgan et al., 2008; Kerchner et al., 2009). Anec- with PCOS incorporated a variety of methods to reduce dotal reports suggest women with PCOS may have energy intake and achieve the weight loss. A range of increased binge eating, food cravings and symptoms of weight loss strategies are available and a patient centred postprandial hypoglycaemia (Herriot et al., 2008). approach that addresses the needs and preferences of However, there remains a paucity of well designed studies patients is important when managing PCOS. Behaviour investigating the eating behaviours or food cravings in change strategies have long been recognised as instru- women with PCOS. mental in managing chronic conditions, particularly It is important to consider the psychological impact of weight management (see Chapter 7.13.2). PCOS when advising sufferers and to involve them in Dietary modification to improve insulin resistance may every part of the care process. produce benefits greater than those achieved by weight loss alone and would also be suitable for lean women with PCOS (Marsh & Brand-Miller, 2005). Modifying car- bohydrate and fatty acid content of the diet have both Clinical management been proposed as methods to improve insulin sensitivity. Management of PCOS focuses on treating the presenting The concept of a low glycaemic index (GI) diet aims to symptoms. Lifestyle management is advocated as the reduce the glycaemic load and hence insulin response to primary therapy in overweight and obese women with ingested foods and drinks. As previously mentioned, PCOS. A modest weight loss of just 5–10%, without hyperinsulinaemia has a detrimental effect on symptoms medical intervention, has been shown to improve many and thus reducing the body’s exposure to insulin may be of the symptoms associated with PCOS (Moran et al., beneficial. The delivery of a low GI diet should incorpo- 2009; 2011), including lower fasting insulin levels, rate healthy eating principles to additionally reduce risk reduced free testosterone and increased SHBG, improved factors for CVD (see Chapter 7.14.1). reproductive function, less hirsutism and an improve- At present only a couple of studies have investigated ment in risk factors for diabetes and CVD. the impact of a low GI diet independent of weight loss in Medical treatments are available for hirsutism, acne and women with PCOS. Marsh et al. (2010) reported greater infertility. Metformin is commonly prescribed for women improvement in insulin sensitivity and regular menses with PCOS as it reduces serum insulin levels in insulin after weight loss with a low GI approach compared to resistant individuals (Diamanti-Kandarakis et al., 2010). weight loss through conventional healthy eating. Both Several studies have revealed some reproductive benefits diets were designed to provide reduced energy, low fat, of metformin and a beneficial effect on serum testoster- low saturated fatty acids and moderate to high fibre; the one concentration has also been observed (Tang et al., low GI diet additionally modified the quality of carbohy- 2010). drate. Twenty-nine women with PCOS followed the low GI diet and 20 completed the healthy eating regimen, and women were followed for 12 months or until they Nutritional consequences achieved 7% weight loss. Barr et al. (2010) demonstrated There are no known nutritional consequences specific to an improvement in insulin sensitivity through an isoca- PCOS. loric diet with a reduction in dietary GI in 21 women with 3.1 Women’s health 77 PCOS over a 12-week intervention period. These studies Further reading provide some evidence to support dietary advice to lean Bailey S. (2011) Nutrition and Polycystic Ovary Syndrome. avail­ women with PCOS, many of whom are also insulin resist- able from PCOS UK. ant. These studies are in agreement with studies that have Bailey S. (2011) Successful Lifestyle Change and Polycystic Ovary indicated enhanced insulin sensitivity in individuals with Syndrome. Available from PCOS UK. type 2 diabetes (Rizkalla et al., 2004). Herriot et al., Elsheikh M, Murphy C. (2008) Polycystic Ovary Syndrome. The (2008; 2009) reported that an isocaloric low glycaemic Facts. Oxford: Oxford University Press. load diet in lean women with PCOS resulted in a reduc- tion in waist circumference. In addition, a reduction in Internet resources carbohydrate craving and general hunger was observed. Fatty acid intake has been shown to influence glucose Verity (a self-help group for women with PCOS) www.verity-pcos metabolism by altering insulin signalling and cell mem-.org.uk PCOS UK www.pcos-uk.org.uk brane function, with a diet high in saturated fatty acids associated with a decrease in insulin sensitivity when compared to a high monounsaturated fatty acid diet References (Galgani et al., 2008). Furthermore, a review by Risérus Amato MC, Verghi M, Galluzzo, A, Giordano C. (2011) The oligomen- (2008) concluded that saturated and trans fatty acids orrhoic phenotypes of polycystic ovary syndrome are character- SECTION 3 should be replaced with poly- (PUFAs) and mono- ized by a high visceral adiposity index: a likely condition of unsaturated fatty acids to improve insulin sensitivity and cardiometabolic risk. Human Reproduction 26: 1486–1494. prevent type 2 diabetes. Phelan et al. (2011) indicated a Azziz R, Woods KS, Reyna R, Key TJ, Knochenhauer ES, Yildiz BO. role for PUFAs in modulating hormones, whereby sup- (2004) The prevalence and features of the polycystic ovary syn- plementation with n-3 PUFA improved the androgenic drome in an unselected population. Journal of Clinical Endo- crinology and Metabolism 89: 2745–2749. profile. Further studies are required to substantiate the Azziz R, Carmina E, Dewailly D, Diamanti-Kandrarakis E, et al. evidence in this area. (2006) Criteria for defining polycystic ovary syndrome as a pre- Increasing physical activity has been shown to improve dominatly hyperandogenic syndrome. Journal of Clinical Endo- glucose metabolism and insulin sensitivity, and to reduce crinology and Metabolism 91: 4237–4245. abdominal adiposity independent of weight loss (Ross Bals-Pratsch M, Großer B, Seifert B, Ortmann O, Seifarth C. (2011) et al., 2004). Benefits are seen without weight loss, and Early onset and high prevalence of gestational diabetes in PCOS thus should be encouraged in all women with PCOS, and insulin resistant women before and after assisted reproduc- tion. Experimental and Clinical Endocrinology & Diabetes irrespective of weight. Eighty-four per cent of women 119(6): 338–342. with PCOS self reported improvements in PCOS symp- Baptiste CG, Battista M-C, Trottier A, Baillargeon J-P. (2010) Insulin toms when they increased their level of physical activity and hyperadrogenism in women with polycystic ovary syndrome. (Jeannes et al., 2009). Barriers to participating in physical Journal of Steroid Biochemistry and Molecular Biolgy 122:, activity, above and beyond those experienced by over- 42–52. weight women without PCOS, include: excess body Barber TM, McCarthy MI, Wass JAH, Franks S. (2006) Obesity and and facial hair, acne, unpredictable menses, body shape polycystic ovary syndrome. Clinical Endocrionology 65: 137–145. concerns, low self esteem and feelings of being Barr S, Reeves S, Sharp K, Jeanes Y. (2010) Efficacy of a low-glycaemic unfeminine. index diet in women with polycystic ovary syndrome. Proceedings A high proportion of women with PCOS report taking of the Nutrition Society 69: E404. nutrient or herbal supplements, which many felt had a Barr S, Hart K, Reeves S, Sharp K, Jeanes Y. (2011) Habitual dietary beneficial effect on their symptoms (Jeannes et al., 2009). intake, eating pattern and physical activity of women with poly- Agnus castus has been proposed to help relieve some cystic ovary syndrome. European Journal of Clinical Nutrition 65: 1126–1132. PCOS symptoms, including restoring menses; however, at Cascella T, Palomba S, De Sio I, et al. (2008) Visceral fat is associated present there are no studies to support this in women with cardiovascular risk in women with polycystic ovary syn- with PCOS. Saw palmetto has been proposed to reduce drome. Human Reproduction 23: 153–159. circulating testosterone and hirsutism, but again there is Chittenden BN, Fullerton G, Maheshwari A, Bhattacharya S. (2009) inadequate evidence to support this. Polycystic ovary syndrome and the risk of gynaecological cancer: A holistic approach to dietary management with con- a systematic review. Reproductive BioMedicine Online 19: sideration of immediate goals (improvement of symp- 398–405. Diamanti-Kandarakis E, Christakou CD., Kandaraki E, Economou FN. toms and fertility, and weight loss) as well as reducing the (2010) Metformin: an old medicine of new fashion: evolving new long term health risks, e.g. of diabetes and CVD, should molecular mechanisms and clinical implications in polycystic be incorporated. Women who are trying to conceive ovary syndrome. European Journal of Clinical Endocrinology should also be following a nutritionally adequate diet 162: 193–212. with folic acid supplements. Dokras A, Clifton S, Futterweit W, Wild R. (2011) Increased risk for abnormal depression scores in women with polycystic ovary syn- drome: a systematic review and meta-analysis. Obstetrics & Gyne- Drug–nutrient interactions cology 117: 145–152. Ehrmann DA, Barnes RB, Rosenfield RL, Cavaghan ML, Imperial J. Oral contraceptives may negatively impact upon insulin (1999) Prevalence of impaired glucose tolerance and diabetes sensitivity and dyslipidaemia. Metformin can cause gas- in women with polycystic ovary syndrome. Diabetes Care 22: trointestinal side effects such as nausea and diarrhoea. 141–146.  78 Section 3: Nutrition in specific groups Ehrmann D, Liljenquist DR, Kasza K, Azziz R, Legro RS, Ghazzi MN; Marsh K, Steinbeck KS, Atkinson FS, Petocz P, Brand-Miller JC (2010) PCOS/Troglitazone Study Group (2006) Prevalence and predictors Effect of a low glycaemic index compared with a conventional of the metabolic syndrome in women with PCOS. Journal of Clini- healthy diet on polycystic ovary syndrome. American Journal of cal Endocrinology and Metabolism 91: 48–53. Clinical Nutrition 92: 83–92. ESHRE and ASRM Sponsored PCOS Consensus Workshop Group Moran LJ, Pasquali R, Teede HJ, Hoeger KM, Norman RJ. (2009) (2004) Revised 2003 consensus on diagnostic criteria and long- Treatment of obesity in polycystic ovary syndrome: a position term health risks related to polycystic ovary syndrome. Fertility statement of the androgen Excess and Polycystic Ovary Syndrome and Sterility 81: 19–25. Society. Fertility and Sterility 92: 1966–82. Fearnley EJ, Marquart L, Spurdle AB, Weinstein P, Webb PM; Austral- Moran LJ, Hutchison SK, Norman RJ, Teede HJ. (2011) Lifestyle ian Ovarian Cancer Study Group & Australian National Endome- changes in women with polycystic ovary syndrome. Cochrane trial Cancer Study Group. (2010) Polycystic ovary syndrome Database of Systematic Reviews 2: CD007506. increases the risk of endometrial cancer in women aged