Search

Samples representative of South Korea, Indonesia, and Peninsular Malaysia were analyzed and the influence of climate on age at menarche was investigated. The sample size was 24,651 for Korea (birth years 1941–1992), for Indonesia 8331 (birth years 1944–1988) plus 20,519 (birth years 1978–1997), and 2842 for Peninsular Malaysia (birth years 1927–1968). Respondents recalled their age at menarche. The mean age at menarche was calculated for each birth year by country, and for Malaysia, additionally by ancestry. It has been found that mean ages at menarche for the early birth years were much younger in Indonesia than in Korea despite similar levels of socioeconomic conditions (proxied by GDP per capita). For example, for the birth year 1944, the mean age at menarche was 14.45 years for Indonesia and 16.19 years for Korea—a difference of 1.74 years. It was necessary to double the Korean GDP per capita to make the Korean mean age at menarche the same as the Indonesian one. Chinese and Malay women in Peninsular Malaysia were further analyzed, and the results provided indirect evidence that the difference between Korea and Indonesia was not due to ancestry differences. Results in multivariate settings provided consistent results. It has been concluded that climate exerts a significant influence on age at menarche because the relatively easy availability of food in the tropics increases energy intake while the absence of cold weather decreases energy expenditure on maintenance and activity. [ABSTRACT FROM AUTHOR]

Background China has a great variety of geographical and climatic conditions, and several cultural differences exist within the country; thus, understanding the regional and seasonal differences that cause skin sensitivities in this country is important. Objective The aim of this study was to assess skin sensitivity of women from six cities in China and from South Korea during the winter and summer seasons to aid the development of suitable and effective dermatological products. Methods This multicentre study included 754 healthy female volunteers, and was conducted in the winter (between January and March) and summer (between June and July) of 2011. Patch tests were performed using 0.5% sodium lauryl sulphate (SLS) aqueous solution and 0.15% retinol in 1,3-butylene glycol on the back of the volunteers. Simultaneously, stinging tests were performed on their cheeks by using 5% lactic acid solution and 0.001% capsaicin solution, each in a negative control vehicle (distilled water and 10% ethanol solution, respectively). Results The patch test results showed that the subjects in Beijing and Shenyang were more sensitive to SLS, retinol and lactic acid in the winter than were those in Guangzhou, Shanghai, Wuhan, Chengdu and South Korea. The stinging test results revealed that the subjects in Beijing were more neurosensitive to lactic acid in the winter; however, during the same season, the subjects from Shanghai and Guangzhou were significantly more neurosensitive to capsaicin. Conclusion Our observations indicate that skin sensitivity differs considerably between women from different parts of China and South Korea. We recommend that these differences be considered during the development of cosmetic products in these countries. [ABSTRACT FROM AUTHOR]