Nutrition in Thalassemia: A Systematic Review of Deficiency, Relations to Morbidity, and Supplementation Recommendations.

BACKGROUND: Reports of nutritional deficiencies in patients with thalassemia (Thal) are common. Despite its importance, however, nutritionally focused research in Thal has been limited by inadequate sample size, inconsistent methodology, a lack of control comparisons, and few interventional trials. Due to these limitations, clinicians lack evidence-based nutrition recommendations to support clinical decision-making. This systematic review summarizes observed relationships between nutrition and morbidity in Thal published in the last 3 decades. METHODS: PubMed, Web of Science, and Embase were screened for articles pertaining to nutrition in Thal using comprehensive search terms. Studies performed in humans, written in English, and published between 1990 and 2020 were included. Over 2100 manuscripts were identified, from which 97 were included. RESULTS: Patients with Thal were most often deficient in vitamins A, C, D, selenium, and zinc. Prevalence of nutritional deficiency was positively correlated with age and iron overload. Evidence to support the role of vitamin D and zinc for bone health was observed; zinc was also found to improve glucose metabolism. CONCLUSIONS: Due to the risk for multinutrient deficiency, nutritional status should be assessed annually in patients with Thal with prompt nutrient replacement when deficiency is detected. Routine supplementation with vitamin D and zinc is recommended.

Precision of the Hologic DXA in the Assessment of Visceral Adipose Tissue.

INTRODUCTION: Visceral fat, also known as visceral adipose tissue (VAT), has been the focus of intensive research over the past several yr, as ground breaking studies have investigated its possible role in predicting long-term cardiac dysfunction, hypertension, and diabetes. Historically, magnetic resonance imaging and computed tomography were the instruments of choice for visceral fat quantification. However, with the introduction of visceral fat assessment software for Dual-energy X-ray Absorptiometry (DXA) scanners, DXA's use for VAT assessment has become increasingly common. To effectively utilize DXA in future VAT research studies, information about their precision and accuracy must be known. This study provides novel information regarding the precision of the Hologic Horizon DXA scanner in the assessment of VAT. METHODS: Sixty individuals (32.7 ± 17.1 yr, 51% male, 40% with body mass index (BMI) > 25 kg/m2) above the age of 16 years were recruited to participate in this study. Subjects found to be pregnant, have a lumbar vertebral compression fracture, nonremovable metal implants in the abdomen, or scoliosis/lordosis/kyphosis were excluded from the study. All subjects underwent 3 consecutive whole body scans on a Hologic Horizon A DXA scanner. RESULTS: VAT mass ranged from 102 g to 1454 g. VAT precision improved with increasing BMI (p = 0.025): coefficient of variation (%CV) was 15.2% for underweight subjects (n = 2), 7.1% for healthy subjects (n = 34), 6.4% for overweight subjects (n = 18), and 4.7% for obese subjects (n = 6). CONCLUSIONS: VAT measurement by Hologic DXA displays a satisfactory level of precision in individuals with a BMI of >18.5 kg/m2. Precision was found to be higher in those with the greatest risk of cardio-metabolic dysfunction (individuals with high VAT). Due to its low cost, brief examination time, noninvasiveness, and limited radiation exposure, DXA may be considered the tool of choice for VAT determination in future studies.

Relationships among Physical Activity, Pain, and Bone Health in Youth and Adults with Thalassemia: An Observational Study.

Patients with thalassemia (Thal) engage in less physical activity than non-Thal populations, which may contribute to pain and osteoporosis. The purpose of this study was to assess relationships between physical activity, pain, and low bone mass in a contemporary sample of patients with Thal. Seventy-one patients with Thal (50 adults ≥18 years, 61% male, 82% transfusion-dependent) completed the Brief Pain Inventory Short Form and validated physical activity questionnaires for youth and adults. Nearly half of the patients reported daily somatic pain. Using multiple regression, after controlling for age and gender, sedentary behavior was positively associated with pain severity (p = 0.017, r 2 = 0.28). Only 37% of adult participants met CDC recommendations for physical activity. Spine BMD Z-score was higher (-2.1 ± 0.7) in those who met activity guidelines compared to those who did not (-2.8 ± 1.2, p = 0.048). A positive relationship was observed between self-reported physical activity (hours/week) and hip BMD Z-score in adults with Thal after controlling for transfusion status and sedentary activity time (p = 0.009, r 2 = 0.25). These results suggest that decreased physical activity and increased sedentary behavior contribute to low bone mass, which may be related to pain severity in some patients with Thal. Studies focused on increasing physical activity may contribute to improved bone health and reduced pain in patients with Thal.

Nutritional Deficiencies Are Common in Patients with Transfusion-Dependent Thalassemia and Associated with Iron Overload.

Patients with thalassemia are frequently deficient in key micronutrients. Attempts to correct these inadequacies through nutritional supplementation have been met with some success, although disparities between intake and circulating levels continue to be observed. This study employed a convenience sample of 41 well-nourished transfusion dependent patients with thalassemia to identify possible mechanisms behind nutritional deficiencies. Each subject completed a Block 2005© Food Frequency Questionnaire (FFQ), through which macro and micronutrient intake was quantified. Fasting blood was drawn to assess vitamins A, C, D, E, copper, selenium, zinc and hematologic parameters. Dietary intake was found to be inadequate compared to Institute of Medicine (IOM) recommendations for many of the fat-soluble vitamins, as well as calcium and zinc. Circulating deficiencies of vitamins C, D, copper, zinc and γ tocopherol were also present in over 20% of patients. Many individuals who consumed an adequate dietary intake had deficient levels of circulating nutrients, which suggest alternative etiologies of nutrient excretion or loss, in addition to higher micronutrient requirements. Liver iron concentration displayed a significant negative relationship with vitamins C (r=-0.62, p<0.001), E (r=-0.37, p=0.03), and zinc (r=-0.35, p=0.037), indicating that in iron-overloaded patients, these nutrients are either endogenously consumed at higher rates or sequestered within the liver, resulting in a functional nutrient deficiency. While this study identified hepatic iron overload to be a significant cause of nutritional deficits commonly observed in patients with thalassemia, multiple etiologies are simultaneously responsible. In response to these findings, nutritional status should be monitored regularly in at-risk patients with thalassemia, and prophylactically addressed with supplementation or aggressive chelation to avoid associated co-morbidities.