Prevalence and causes of anemia among older adults in India: findings from wave 2 of the Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD)

Anemia among older adults aged ≥ 60 years is a well-described risk factor that increases the risk of falls, cardiovascular diseases, and mortality. In India, objectively measured national estimates of anemia prevalence and the causes of anemia among older adults are lacking. The Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD) collected venous blood samples from a nationally representative sample of 3,252 individuals in wave 2 of the study. Out of these, 3,009 samples were used to estimate national prevalence and regional differences in anemia prevalence and its underlying causes. Anemia was defined as hemoglobin < 13 mg/dl in males and < 12 mg/dl in females and further categorized into nutritional and non-nutritional anemia based on several nutritional (ferritin, Vitamin B12, and folate), inflammatory (ferritin, C-reactive protein), and renal (serum creatinine) biomarkers. The overall national anemia prevalence was 49.92%. Anemia prevalence was significantly higher among women (53.9%) than men (45.8%). Among those with anemia, nutritional anemia was found in 63.5% of the respondents, with isolated iron deficiency anemia being the most common cause (51.8%). Among the non-nutritional category, anemia of chronic disease was the most common type (31.4%). About 10% of all anemia cases could not be classified into either category using the available data. Regional differences were seen with the highest prevalence of anemia in Assam, West Bengal, Jharkhand, and Odisha, and the lowest prevalence (< 30%) in Jammu & Kashmir and Haryana. Multivariate adjustment showed that age, sex, and region of residence are independently associated with anemia status. The study provides valuable insights into the overall anemia prevalence among older adults in India, its underlying causes, and regional differences to lay a strong foundation for making informed decisions toward anemia control in India.