Impact of Renal Function and Demographic/Anthropomorphic Variables on Peak Thyrotropin After Recombinant Human Thyrotropin Stimulation: A Stepwise Forward Multiple-Regression Analysis

Abstract

Identifying those patients with a favorable combination of parameters predicting a high-peak TSH is the first step toward an individualization of rhTSH dosing. Additionally, the subsequent TSH decrease over time needs to be taken into account. A complete understanding of the interrelation of the identified key parameters and both the TSH peak and subsequent TSH pharmacokinetics might allow for a more personalized rhTSH dosage strategy to achieve sufficient TSH levels instead of the fixed dosing procedure used at present.

Analysis of Clinical Factors for the Determination of Optimal Serum Level of Thyrotropin After Recombinant Human Thyroid-Stimulating Hormone Administration

“…Although our study analyzed a more comprehensive list of variables, in a relatively large sample size, our results were similar to those of previous studies for most parameters. For example, our results regarding age corroborated the data of previous reports [11][12][13]. Over et al [13] have previously hypothesized that any effects that were apparently exerted by altered renal function, or altered metabolism in fat or lean mass compartments, might ultimately be caused by agerelated changes.…”

“…However, this dosage and protocol was developed and prepared in Western countries, particularly in the USA, where anthropometric parameters in the general population are markedly different than in the Korean population. We observed wide variability in the degree of the increase in serum levels of TSH, and our peak levels of TSH were far higher than those that have been previously reported [10,11,13,14]. Therefore, we speculate that the standard dose of rhTSH can be lowered, or the standard injection protocol can be modified, if the patient has a small height and low body weight, as our results indicate that the levels of peak serum TSH are dependent upon anthropometric parameters.…”

“…However, they included only 98 of 311 patients in their subgroup analyses and measured TSH on day 5 after rhTSH injection, which might have affected the accuracy of their analysis. More recently, Hautzel et al [11] have reported that serum creatinine had the second greatest impact on peak serum TSH levels after rhTSH injection, with BSA having the greatest impact. As predicted, the mean values for weight, height, and BSA (calculated using the DuBois formula with weight and height) were far higher in their study, compared with those in our patient group (weight, 78.6±19.4 kg vs 61.9 ±11.1 kg; height, 1.70±0.09 m vs 1.61±0.08 m; BSA, 1.89± 0.24 m 2 vs 1.65±0.16 m 2 ).…”

“…Therefore, we speculate that the standard dose of rhTSH can be lowered, or the standard injection protocol can be modified, if the patient has a small height and low body weight, as our results indicate that the levels of peak serum TSH are dependent upon anthropometric parameters. A number of previous studies have also attempted to demonstrate that anthropometric parameters can predict the peak level of TSH after rhTSH administration [10][11][12][13][14], although these were typically performed in Western countries. Thus, we evaluated the influence of a more extensive list of demographic and anthropometric parameters on the peak levels of serum TSH after rhTSH injection in a non-Western population.…”

“…These results indicate that it may be possible to lower the dose for each injection in some subjects, or that a single dose of rhTSH might be sufficient to achieve TSH stimulation [9]. Interestingly, several anthropometric and demographic parameters, including age, sex, height, body surface area (BSA), lean body mass, and renal function have been reported to influence peak levels of serum TSH after rhTSH injection, although conflicting results have also been reported in various studies [10][11][12][13][14]. Therefore, it is not clear whether the effect of rhTSH is mediated solely by the patient's body composition, or whether different clinical situations, such as ablation of remnant thyroid tissue or diagnostic testing after surgery (followed by radioiodine ablation), may also mediate the effect of rhTSH.…”