[The Relationship between Body Mass Index and Adult Acute Myeloid Leukemia]

To analysis the relationship between different BMI (body mass index) and the clinical characteristics, laboratory examination indexes of newly diagnosed adult patients with acute myeloid leukemia (AML), so as to investigate the effects of BMI to the efficacy of first induction chemotherapy.

The clinical data of 145 newly diagnosed adult AML patients treated in the First Hospital of Lanzhou University from August 2015 to August 2019 were retrospective analyzed. According to the guidelines for prevention and control of overweight and obesity in Chinese adults, the BMI (kg/m²) of the selected AML patients before induction chemotherapy was calculated and the patients were divided into the low body mass group (BMI<18.5), the normal body mass group (18.5 ≤BMI ≤23.9) and the overweight and obese group (BMI ≥24). The clinical data of the patients, including sex, age, risk stratification,the types of leukemia, gene mutation, complications, length of hospital stay and other clinical features; white blood cell (WBC), hemoglobin (Hb), albumin, triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL), low density lipoprotein (LDL), lactate dehydrogenase (LDH), and other laboratory index; agra-nulocytosis with fever, infection of etiology, lack of granulocyte duration, significant bleeding, liver and kidney toxicity of chemotherapy adverse reactions associated indicators and Morphological remission were collected. The induction chemotherapy regimen was the standard chemotherapy regimen (anthracyclines combined with cytarabine).

Among the 145 newly diagnosed adult AML patients, there were 71 males and 74 females. The median age was 50 years old(range 18 to 82 years old). There were 21 patients in underweight group (14.5%), 79 patients in normal weight group (54.5%), and 45 patients in overweight and obese group (31.0%). The patients with higher BMI level showed the older in age（P=0.018）. There were significant differences in sex between the patients in each group(P=0.035). In overweight and obese patients, the number of male was significantly higher than female. There were no statistical differences in AML classification, comorbidities(Diabetes, hypertension, coronary heart disease), hospital days, whether secondary AML and FLT3 gene mutation among the patients in different BMI groups. There were significant differences in TG of the patients in the different groups, the overweight and obese patients were higher (P=0.007). There were no significant differences in WBC and Hb counts, ALB, TC, HDL, LDL, or LDH between the patients in each BMI group at newly diagnosed. The complete remission rate of the patients in the low body mass group or overweight and obese group were lower than that in the normal body weight group (P=0.035). The rate of documented infection during the first induction chemotherapy were significantly higher for the patients in low body mass group than those in normal weight group or overweight and obese group (P=0.038). There was no statistical difference in chemotherapy regimens, the number of chemotherapy until CR, febrile neutropenia, bleeding, and the time of neutropenia, liver and kidney toxicity among each BMI group. Multivariate analysis showed that overweight and obese (P=0.012) , FLT3 mutation (P=0.015) were the risk factors affecting the CR rate of the patients. And the patients with secondary AML, high-risk type, and newly diagnosed WBC ≥50×10⁹/L showed lower CR rate, but there was no statistical difference in the patients of each group.

In newly diagnosed adult patients with AML, low body mass, overweight and obesity, and FLT3 mutations were the factors reducing the early efficacy of AML patients. There were more adverse reactions induced by chemotherapy in the low body mass group. Therefore, inappropriate BMI level can be a risk factor for assessing the prognosis of adults with newly diagnosed AML.