Sarcopenia is a common clinical condition among elderly people. It is a syndrome characterized by progressive and generalized loss of skeletal muscle mass, strength, and muscle function [1] . Sarcopenia is associated with weakness, loss of independence, disability, higher risk of falls, and a decrease in quality of life [2] -[4] . The significant clinical impact of sarcopenia and its high costs both direct and indirect that this condition generates emphasizes the need of health care systems to focus on this geriatric syndrome [5] -[7] .

The epidemiological data available indicates that the prevalence of sarcopenia varies widely; this variation is related to the different populations being studied, ages, gender, different settings and different diagnostic criteria selected by the researchers [5] -[8] .

Although the prevalence of sarcopenia in elderly people has been broadly investigated in the Unites States, European countries and to a lesser extent in Asian countries, there are no reports on the prevalence of sarcopenia in the African countries. There is no data on the epidemiology of sarcopenia in Egypt neither in nursing home residents nor community dwelling elderly. So we conducted this study to evaluate the prevalence of sarcopenia among nursing home older residents in Cairo .

All participants were subjected to complete medical history taking including history of physical activity [9] [10] , assessment of body mass index (BMI) [11] , and assessment of sarcopenia by the use of the European Working Group on Sarcopenia in Older People (EWGSOP) recommendation [12] .

Our study involves 357 elderly aged 60 years and more. The mean age of study participants was 70.7 ± 7.8 years. 50.4% of participants were women. 51.5% were educated ≤12 years and the rest were educated >12 years. As regard marital status 17.1% are married and 82.9% are singles. 19.6% were working physical work, 52.1% were working mental work and the rest had no previous occupation. Participants^, BMI ranged between 17.5 - 25 kg/m². 55.2% of participants do regular physical activity. 43.7% of participants have hypertension, 26.1% have diabetes mellitus, 19.0% have ischemic heart disease (IHD), 19.6% have heart failure, 3.9% had previous history of stroke, 13.2% have osteoarthritis, 3.1% have chronic liver disease (CLD), and 62.2% have chronic obstructive pulmonary disease (COPD).

The prevalence of sarcopenia among nursing home older residents in Cairo was 17.7%; 22.2% in elderly men and 14.4% in elderly women.

The study detected significant associations between sarcopenia and age (p = 0.018) as well as between sarcopenia and BMI (p = 0.030). Those with sarcopenia were less likely to be involved in regular physical activity (p = 0.002). There were no significant associations between sarcopenia and presence of co-morbidities (p > 0.05) except for ischemic heart disease (IHD) which was significantly detected among residents with sarcopenia (p = 0.045) (Table 1).

In the present study, we assessed the prevalence of sarcopenia among nursing home older residents in Cairo. Our findings showed that the prevalence of sarcopenia, using the EWGSOP recommendation, is 17.7%; 22.2% among elderly men and 14.4% among elderly women.

In 1980, a first study was performed in the United States to assess this problem. They examined 115 nursing home residents and documented that 85% of the studied participants have a low mid arm circumference [16] . In Saudi Arabia, data from 84 nursing home male residents (their age ranged between 24 - 80 years) showed a low mid arm circumference in 40% of residents [17] . In Turkey, Bahat and colleagues [8] have investigated the prevalence of sarcopenia in 157 elderly male residents in one nursing home (their mean age was 73.1 ± 6.7 years) using BIA. They reported that the prevalence of sarcopenia was 85.4%. In Israel, the prevalence of skeletal muscle mass abnormalities in 109 nursing home residents was 67.0%; 97.8% in males and 43.8% in females [18] . In Italy, Landi et al., 2012 [19] conducted their study on 122 nursing home residents, their mean age was 84.1 ± 6.9. They used the EWGSOP recommendation for diagnosing sarcopenia as in the current study. They found that 32.8% were identified as affected by sarcopenia and it was more common in men (68%) than in women (21%). The results of the current study showed lower prevalence than that reported previously. The higher prevalence in the aforementioned studies [8] [16] -[19] may be due to small samples size, the usage of different measurement techniques, different studied populations and environmental difference. Regarding Egypt’s environment, Egypt is a country that the whole year is bathing almost in perpetual sunshine. Life course studies suggest that a modest but significant proportion of the origins of sarcopenia may be related to the environment. It was demonstrated that sun exposure may have important benefit for the prevention of muscle mass and functional declines in older adults [20] . Vitamin D, which has an important role in the maintenance of muscle function for older adults, is produced endogenously when ultraviolet rays from sunlight strike the skin and

trigger vitamin D synthesis [21] .

In this study there is a significant association between age and sarcopenia (p = 0.018). This is consistent with the findings of previous studies [16] -[19] [22] . Aging is associated with significant changes in body composition, with a substantial reduction in fat free mass and an increase in visceral fat [12] . As well as, the age-dependent decrease in anabolic hormones, such as testosterone, estrogen, growth hormone, and insulin like growth factor-1 (IGF-1), may lead to loss of skeletal muscle mass [23] [24] .

This study reported a significant association between BMI and sarcopenia (p = 0.031). This is consistent with the information reported by previous studies who documented the association between underweight and sarcopenia [4] [8] [25] .

Previous studies [4] [26] [27] and the current study found a significant association between physical activity and sarcopenia (p = 0.002). Lack of physical activity has been shown to be a risk factor for muscle weakness that, in turn, results in loss of muscle mass and muscle strength [26] [27] .

Previous studies [24] [28] as well as this study found that IHD was significantly associated with the presence of sarcopenia (p = 0.045). This may be due to the reported association between sedentary life style and the two diseases either IHD [29] or sarcopenia [26] . As well as, in IHD patients there is limitation in carrying out physical activities due to fear of ischemic chest pain or anticipation of pain [30] . This lack of physical activity will lead to sarcopenia.

The prevalence of sarcopenia using the EWGSOP recommendation was 22.2% and 14.4% in elderly men and women respectively. Age, underweight and lack of physical activity were found to be associated with sarcopenia in nursing home older residents in Cairo.

There is no conflict of interest.