Age Modifies the Response to Recombinant Human Thyrotropin

Abstract

Both days 3 and 5 TSH concentrations were higher in older individuals after rhTSH administration. This finding did not appear to be related to body weight, body mass index, or glomerular filtration rate in a simple manner. The TSH concentration achieved may be a result of complex interactions between distribution within fat and muscle body compartments, hepatic function, and renal function. Prospective studies could examine whether the magnitude of the TSH elevation after rhTSH administration affects diagnostic or therapeutic efficacy.

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

“…Furthermore, by help of the stepwise forward multiple linear regression, these parameters were weighted according to their effect size on the prediction of the depending variable peak TSH with BSA and renal function as most relevant followed by age, sex, and height ( Fig. 2A) (11)(12)(13). Regarding the impact of sex, our findings corroborated the data of Montesano et al and Castagna et al, even if the latter did not test sex by multivariate means (10,11).…”

“…The results of the two patients from our study who also demonstrated a severely impaired renal function further support the proposition of a direct impact of kidney function on the blood TSH concentration after rhTSH as the one who is on hemodialysis presented with a creatinine of 7.4 mg/dL (GFR 7.9 mL/1.73 m 2 per minute) and a concomitant peak TSH of 385.9 mU/L, while the other demonstrated a creatinine of 4.1 mg/dL (GFR 10.6 mL/1.73 m 2 per minute) and a TSH of 196.0 mU/L. However, the other studies systematically investigating the influence of renal function on the resulting peak TSH failed to demonstrate any significant correlation by means of multivariate comparisons (11,12). Over et al found a positive correlation in their univariate analysis that was no longer significant applying multivariate statistics (12).…”

“…However, the other studies systematically investigating the influence of renal function on the resulting peak TSH failed to demonstrate any significant correlation by means of multivariate comparisons (11,12). Over et al found a positive correlation in their univariate analysis that was no longer significant applying multivariate statistics (12). The missing correlation in the multivariate approach might be due to their comparably lower group size (n = 112).…”

“…However, the resulting TSH levels demonstrate a wide range of variability with the majority of values far beyond the reported TSH range. A number of previous studies attempted to identify those parameters that predict the height of the peak TSH after rhTSH administration, but the multivariate analyses applied there yielded inconclusive results (10)(11)(12)(13). Therefore, to achieve the objective of an individualized rhTSH application scheme, the question of influencing parameters on peak TSH ought to be readdressed in a large patient sample with a special interest in the impact of renal function on peak TSH.…”

“…According to previous uniand multivariate studies, several demographic and anthropometric parameters, including body surface area (BSA), age, sex, and lean body mass (LBM), seem to influence this TSH response to rhTSH, but different, partly conflicting results have been published (10)(11)(12)(13). Especially regarding the glomerular filtration rate (GFR) and creatinine as surrogate markers of renal function, no correlation with TSH concentration was found (11,12). This is rather surprising, given that the kidneys are known to be a key organ for pituitary-derived TSH clearance (4,5,9).…”