Perspective

Treatment of Graves’ disease may increase body weight, BMI in children

Children with pediatric Graves’ disease experienced excessive, sustained weight gain after receiving treatment for the condition, researchers reported in a new study.

Previous research has associated increased body weight with treatment for Graves’ disease in adults; however, data on this connection in the pediatric population is lacking. Scott A. Rivkees, MD, and colleagues at the department of pediatrics and Yale Pediatric Thyroid Center at Yale University School of Medicine measured changes in body weight and BMI before and after treatment for Graves’ disease in children aged 4 to 18.5 years seen at their medical center before and after treatment.

The researchers analyzed height and weight data for 3.6 years before diagnosis and 3.1 years after treatment. Of the 43 patients included in the study, 29 had normal BMIs, eight were overweight and five were obese. The average BMI was 18.4 and the average BMI z score was –0.02 at the beginning of treatment, both of which did not differ from the normal population (P=.921) or the period before treatment (P=.07). BMI z scores, however, decreased significantly during the period leading up to diagnosis among the overweight and obese patients (P<.05), the researchers said.

After initiation of treatment, BMI and average BMI z scores increased considerably, with most of the weight gain occurring during the first 6 months of treatment. The patients’ average BMI and average BMI z score increased significantly to 19.8 and 0.45, respectively (P<.0001), during the first 3 months of treatment. Similarly, at 6 months, mean BMI z score climbed to 0.79. They also stabilized at higher values than those observed during the pretreatment period (P<.0001) and remained elevated in approximately 25% of patients, according to the researchers.

Treatments for Graves’ disease ranged from antithyroid medications, including propylthiouracil and methimazole, total thyroidectomy and radioactive iodine.

“Conventional wisdom is that many children with Graves’ disease present with weight loss and that the condition is associated with a return to normal body weight with treatment,” Rivkees told Endocrine Today. However, many children with Graves’ disease “do not present thin,” which is likely due to hyperphagia, which is common in this condition.

“Furthermore, within 3 to 6 months of treatment onset, while still biochemically hyperthyroid, they gain excessive amounts of weight and the excessive weight persists for years,” he said. “As such, parents and their children need to be cautioned to curb the excessive eating patterns that take hold when the disease is evolving and follow body weight closely as the hyperthyroid state is improving.” – by Melissa Foster

Disclosure: Dr. Rivkees and colleagues report no relevant financial disclosures.

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PERSPECTIVE

Graves’ hyperthyroidism is characterized by a hypermetabolic state; historically, weight loss despite an increased appetite, is a common presenting feature in children. By way of contrast, this nicely detailed study by van Veenendall and Rivkees from Yale University School of Medicine reports that BMI 1 year before diagnosis was +0.25 SD; at diagnosis BMI had fallen to –.02 SD (i.e., normal); and 6 months after treatment, BMI rose to +0.79 SD, above premorbid BMI. With monitoring for up to 3 years after diagnosis, boys tended to return to premorbid BMI, but girls persisted with excessive weight gain. Are we surprised? Not really. Presumably, this current generation of children was able to increase caloric intake during the time hyperthyroidism developed, so as to maintain weight. Further, presumably in some (mostly girls), this increase in calorie intake did not abate once treatment restored euthyroidism. As is true of the current obesity epidemic, likely decreased physical activity was a factor. The implication of this study is that physicians must provide anticipatory counseling on diet and exercise as children with hyperthyroidism undergo treatment.

– Stephen LaFranchi, MD

Professor, Department of Pediatrics

Oregon Health & Sciences University

Disclosure: Dr. LaFranchi reports no relevant financial disclosures.

Twitter Follow EndocrineToday.com on Twitter.

Children with pediatric Graves’ disease experienced excessive, sustained weight gain after receiving treatment for the condition, researchers reported in a new study.

Previous research has associated increased body weight with treatment for Graves’ disease in adults; however, data on this connection in the pediatric population is lacking. Scott A. Rivkees, MD, and colleagues at the department of pediatrics and Yale Pediatric Thyroid Center at Yale University School of Medicine measured changes in body weight and BMI before and after treatment for Graves’ disease in children aged 4 to 18.5 years seen at their medical center before and after treatment.

The researchers analyzed height and weight data for 3.6 years before diagnosis and 3.1 years after treatment. Of the 43 patients included in the study, 29 had normal BMIs, eight were overweight and five were obese. The average BMI was 18.4 and the average BMI z score was –0.02 at the beginning of treatment, both of which did not differ from the normal population (P=.921) or the period before treatment (P=.07). BMI z scores, however, decreased significantly during the period leading up to diagnosis among the overweight and obese patients (P<.05), the researchers said.

After initiation of treatment, BMI and average BMI z scores increased considerably, with most of the weight gain occurring during the first 6 months of treatment. The patients’ average BMI and average BMI z score increased significantly to 19.8 and 0.45, respectively (P<.0001), during the first 3 months of treatment. Similarly, at 6 months, mean BMI z score climbed to 0.79. They also stabilized at higher values than those observed during the pretreatment period (P<.0001) and remained elevated in approximately 25% of patients, according to the researchers.

Treatments for Graves’ disease ranged from antithyroid medications, including propylthiouracil and methimazole, total thyroidectomy and radioactive iodine.

“Conventional wisdom is that many children with Graves’ disease present with weight loss and that the condition is associated with a return to normal body weight with treatment,” Rivkees told Endocrine Today. However, many children with Graves’ disease “do not present thin,” which is likely due to hyperphagia, which is common in this condition.

“Furthermore, within 3 to 6 months of treatment onset, while still biochemically hyperthyroid, they gain excessive amounts of weight and the excessive weight persists for years,” he said. “As such, parents and their children need to be cautioned to curb the excessive eating patterns that take hold when the disease is evolving and follow body weight closely as the hyperthyroid state is improving.” – by Melissa Foster

Disclosure: Dr. Rivkees and colleagues report no relevant financial disclosures.

For more information:


PERSPECTIVE

Graves’ hyperthyroidism is characterized by a hypermetabolic state; historically, weight loss despite an increased appetite, is a common presenting feature in children. By way of contrast, this nicely detailed study by van Veenendall and Rivkees from Yale University School of Medicine reports that BMI 1 year before diagnosis was +0.25 SD; at diagnosis BMI had fallen to –.02 SD (i.e., normal); and 6 months after treatment, BMI rose to +0.79 SD, above premorbid BMI. With monitoring for up to 3 years after diagnosis, boys tended to return to premorbid BMI, but girls persisted with excessive weight gain. Are we surprised? Not really. Presumably, this current generation of children was able to increase caloric intake during the time hyperthyroidism developed, so as to maintain weight. Further, presumably in some (mostly girls), this increase in calorie intake did not abate once treatment restored euthyroidism. As is true of the current obesity epidemic, likely decreased physical activity was a factor. The implication of this study is that physicians must provide anticipatory counseling on diet and exercise as children with hyperthyroidism undergo treatment.

– Stephen LaFranchi, MD

Professor, Department of Pediatrics

Oregon Health & Sciences University

Disclosure: Dr. LaFranchi reports no relevant financial disclosures.

Twitter Follow EndocrineToday.com on Twitter.