Associations between dietary patterns and risk of sarcopenia in Korean postmenopausal women

Abstract

근감소증(sarcopenia)은 노화에 따른 보편적인 신체변화 중 하나로, 근육량 감소 뿐 아니라 근력의 저하 및 수행기능의 감소에 대한 개념도 포함한다. 근감소증의 발병과 관련된 위험인자로는 나이, 성별, 인종, 음주, 흡연, 신체 활동, 식이 섭취 등이 알려져 있다. 식이 요인 중 단일 영양소로는 단백질이나 비타민 D가, 식품군으로는 채소와 과일 섭취가 근감소증의 위험을 낮추는 것과 관련 있는 것으로 보고되고 된 바 있으며, 최근에는 단일영양소 혹은 식품보다는 식사패턴에 대한 연구가 진행되고 있다. 염증과 산화적 스트레스는 근감소증의 발병과 관련된 메커니즘의 일부로 제시되어왔다. 여성은 폐경 후 에스트로겐 수준의 감소로 인해 산화적 스트레스가 증가된다. 비타민 E, 비타민 C, 카로티노이드와 같은 항산화 영양소는 근육 감소에 대한 위험을 감소시키는데 긍정적인 역할을 하는 것으로 보고되어 왔다. 따라서 본 연구는 국민건강영양조사 (KNHANES, 2008-2011) 4기와 5기에 참여한 1548명의 폐경기 여성(45세-86세)을 대상으로 근감소증과 관련된 식사패턴을 알아보고자 진행되었으며, 또한 단일 영양소나 식품의 수준에서도 근감소증과의 관련성이 나타나는지를 함께 살펴보았다. 24시간 회상법을 통한 식품섭취자료를 이용하여 요인분석을 실시한 결과, '다양식', '서양식', '전통식'과 '간식 및 음료'의 4 가지 식시패턴이 도출되었다. 이 중 '서양식' 섭취 패턴은 더 높은 교육상태, 도시 거주자, 더 높은 가계 소득 및 식이 보충제 복용과 관련이 있었다. '서양식' 패턴의 높은 점수를 가지고 있는 폐경 여성은 지방으로부터의 에너지 섭취 비율이 높고, 나트륨 섭취량이 낮은 것으로 나타났다. 결과적으로 교란변수를 보정한 후, '서양식' 식사패턴 점수의 최상위3분위군이 최하위 1분위군에 비해 근감소증에 대한 오즈비가 64.8 % 높은 것으로 나타났다 (p for trend = 0.0105). 영양소나 식품군 수준에서의 섭취상태와 근감소증과의 관련성을 살펴본 결과, 근감소증과의 관련성 나타난 영양소나 식품군은 없었다. 다만, 에너지 (β = 0.002, p = 0.0091), 식이섬유 (β = 0.0174, p = 0.0532), 비타민 C (β = 0.0015, p = 0.0216) 및 β- 크립토잔틴 (β = 0.0575, p = 0.0575) 섭취는 근육량과 양의 관련성이 있는 것으로 나타났다. 이상의 결과를 통해, 산화적 스트레스를 악화시킬 수 있는 '서양식'과 같은 식사패턴이 폐경기 여성의 근감소증의 높은 위험과 관련이 있음을 확인할 수 있었다. 따라서, 폐경 후 에스트로겐 감소로 인해 더 높은 산화적 스트레스 상황에 놓이게 되는 폐경 여성의 경우, 서양식에 포함된 가공육, 달걀, 치즈 및 밀가루와 빵류를 너무 많이 섭취하지 않도록 권고할 필요성이 있는 것으로 사료된다. ;Sarcopenia is one of the common disease conditions affecting the elderly. Sarcopenia, also known as ‘anorexia of aging’ is defined as loss of muscle mass or/and muscle function. The current knowledge on etiology of sarcopenia, pathological mechanisms, diagnosis criteria and the role of dietary intake in sarcopenia were reviewed in this report. Sarcopenia can be categorized into primary sarcopenia or secondary sarcopenia. Primary sarcopenia is the loss of muscle mass due to aging. Secondary sarcopenia can be activity-related, disease-related or nutrition-related. The various risk factors involved in the development of secondary sarcopenia include cigarette smoking, alcohol consumption, sedentary lifestyle/physical activity, oxidative stress/inflammation, disease status, body mass/obesity, malnutrition and gastrointestinal disorders. Though the existence of various diagnosis definitions makes it difficult to estimate the exact prevalence of sarcopenia, it is approximated that 0.1% to 85.4% of the population suffers from sarcopenia. The lack of consensus in the diagnosis criteria points out the importance of a universal diagnosis criterion for sarcopenia based on sex, ethnicity or disease status. Existing literature has reported that intake of single nutrients such as protein and vitamin D and food groups such as vegetables and fruits are associated with lowering the risk of sarcopenia. In recent years, research has been conducted with a focus on dietary patterns rather than single nutrients or food groups. ‘Mediterranean’ pattern, ‘Prudent’ pattern and ‘Vegetables-Fruits’ pattern have been associated with lower risk of sarcopenia. The metabolic acidosis plays an important role in the etiology of sarcopenia. Alkalinogenic foods such as fruits and vegetables, and acidogenic foods including protein-rich food such as meat, eggs and dairy products are the main food groups involved in the acid-base load in the body. Hence, better understanding of the acid-based load in the body and its role in development of sarcopenia through combination of food groups such as fruits and vegetables and protein rich food groups are necessary. This further reiterates the necessity of more dietary pattern studies on the development of sarcopenia. Inflammation and oxidative stress have been suggested to play a part in the mechanism associated with the onset of sarcopenia. Women have increased oxidative stress due to decrease in estrogen levels with aging and after menopause. Antioxidant nutrients such as vitamin E, vitamin C, and carotenoids have been reported to play a positive role in reducing the risk of muscle loss. Therefore, a cross-sectional study was conducted to investigate the associations between dietary pattern derived by factor analysis and sarcopenia in 1,548 postmenopausal women (45-86 years old), who participated in the fourth and fifth Korean National Health and Nutrition Examination Survey (KNHANES, 2008-2011). This study also aimed to investigate the whether there is a relationship between a single nutrients or food groups and sarcopenia. Using factor analysis, four different dietary patterns, ‘Diverse,’ ‘Western,’ ‘Traditional’ and ‘Snacks and beverages’ were obtained in our study population. Postmenopausal women with higher scores for the ‘Western’ pattern had higher education status, was likely to be a resident of urban location, had higher household income and was likely to use dietary supplements. Postmenopausal women with higher scores for the ‘Western’ pattern had higher energy from fat and higher intakes of sodium. Further, postmenopausal women in the highest tertile of ‘Western’ had 64.8% higher odds of sarcopenia after adjustment for potential confounding factors (p for trend = 0.0105). When the association between single nutrients or food groups and sarcopenia was examined, no significant association was observed after adjusting for potential confounding factors. After adjusting for confounding factors, energy (β=0.002, p-value=0.0091), fiber (β=0.0174, p-value=0.0532), vitamin C (β=0.0015, p-value=0.0216) and β-cryptoxanthin (β=0.0575, p-value=0.0575) were positively related with muscle mass. These results suggest that dietary pattern such as ‘Western’ maybe associated with higher risk of sarcopenia in Korean postmenopausal women who are at high risk for oxidative stress as a result of reduced estrogen levels.