[Anemia status and its relevant factors among elderly people aged above 80 years old in longevity areas in China]

To describe the epidemiological characteristics of anemia among elderly people aged 80 years old and above in longevity areas in China and to analyze its relevant factors to the health effects.

The data used in this study came from the Chinese Longitudinal Healthy Longevity Survey, including all centenarians in 7 longevity areas, as well as randomly selected population aged 40-, 60-, 80- and 90- in the same 7 areas. A total of 1980 subjects enrolled in the study. The data of general information, eating habits and diseases history was collected by questionnaire survey. Hemoglobin, plasma macro and trace elements were gained by biochemical test. Logistic regression was used to analyze the anemia and its relevant factors.

The prevalence of anemia of elderly people aged 40-, 60-, 80-, 90-, 100- were 16.1% (75/465), 19.1% (82/429), 41.1% (141/343), 46.2% (171/370) and 57.1% (213/373) in 7 longevity areas, which kept on a rise with the increasing of age (z = 14.7, P < 0.05). The prevalence of anemia of male aged 100 years old and above was 66.7% (38/57), which was the highest one among all elderly. Plasma Ca (2.96 mmol/L), Fe (58.22 micromol/L), Zn (28.84 micromol/L) and Cu (19.56 micromol/L) of the elderly people aged 90 years old and above in anemia group, and in control group they were 3.30 mmol/L, 78.26 micromol/L, 33.66 micromol/L, 20.62 micromol/L, respectively. The significant differences were observed between the two groups (z values were -2.95, -3.07, -2.23 and -2.16, P < 0.05). The main risk factors related to anemia were age (OR = 1.675, 95%CI: 1.554 - 1.807), followed by frequency of beans and their products intake (OR = 0.545, 95%CI: 0.435 - 0.682), waist circumference (OR = 0.567, 95%CI: 0.456 - 0.705) and frequency of meat intake (OR = 1.608, 95%CI: 1.303 - 1.983).

The anemia status of oldest old people in longevity areas was severe. Higher frequency of beans and their products intake and maintaining well nutritional condition benefit for the prevention of anemia.