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James V Hennessey

Publications and source records attributed to James V Hennessey.

7 recordsLinked to original sources
PubMed2005

Muscle carnitine in hypo- and hyperthyroidism.

Weakness is common in both hyper- and hypothyroidism, and skeletal muscle L-carnitine may play a role in this regard, as suggested by studies indicating abnormal levels of carnitine in serum and urine of patients with thyroid dysfunction. Skeletal muscle samples were obtained for carnitine analysis from control subjects, and from hyperthyroid and hypothyroid patients before and after treatment. There was a significant reduction in carnitine, especially the esterified portion, in hyperthyroid individuals, with a return to normal as euthyroid status was regained. In hypothyroid patients, there was a trend for carnitine to be lower than normal and for improvement once euthyroid status was attained. Our data indicate that muscle carnitine levels are affected by both hypo- and hyperthyroidism. A decrease in muscle carnitine in both conditions may contribute to thyroid myopathy.

Adult↗
PubMed2004

Two-week low iodine diet is necessary for adequate outpatient preparation for radioiodine rhTSH scanning in patients taking levothyroxine.

We evaluated a self-managed, outpatient, low iodine diet (LID) (<50 microg/day) designed to decrease total body iodine (TBI) in preparation for radioiodine (131I) scans. However, levothyroxine (LT4) ingestion is a significant source of dietary iodine in recombinant human TSH (rhTSH)-stimulated studies. Measuring urine iodine to creatinine ratios (I/Cr), a reflection of TBI, we evaluated the LID for 7-day and 14-day periods to determine the efficacy of our LID to deplete TBI, with and without LT4. Patients following the LID for 14 days (n = 28) without LT4 attained the goal of an iodine deficient state (I/Cr <50 microg/g) in 78% of cases, establishing the diet's efficacy in significantly reducing TBI. In patients taking LT4, 7 days of the LID was insufficient to attain this goal of true iodine deficiency. However, a 14 day LID while taking LT4 resulted in 21% of patients being iodine deficient. For diagnostic purposes, a 7 day LID period (n = 21) suboptimally but adequately (I/Cr <100 microg/g) prepared 41% of the patients, whereas 14 days on the diet (n = 24) adequately prepared 71% of the patients taking LT4. Our simple, self-managed, outpatient, LID effectively makes patients iodine deficient. Though less efficacious when taking LT4, this LID adequately reduces TBI for rhTSH-stimulated 131I uptake scans when followed for 14 days.

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