During a 3-year period, 233 patients with papillary thyroid cancer were seen at King Faisal Specialist Hospital (KFSH) (79% were female; 94% were national subjects). Pathology revealed 88% pure papillary carcinoma and 12% mixed papillary and follicular carcinoma, 7% microfocus, 18% well encapsulated, 24% capsular invasion, and 51% soft tissue invasion. Thirty percent of patients who had initial surgery not done at KFSH compared with 93% of patients who had initial surgery done at KFSH had an I-123 24-hour uptake < 5%. One hundred seventeen patients required completion thyroidectomy at KFSH for significant residual thyroid tissue, 56% of those had residual papillary carcinoma. The amenability of papillary thyroid cancer for cure necessitates the optimization of management at the national level. In Saudi Arabia, papillary thyroid cancer presented in an advanced stage, especially in males as manifested by the large primary tumor size, advance pathologic staging, and distant metastases at the time of presentation. Findings at second surgery, showed significant residual disease.

Previous studies addressing the interaction of age and sex with the function of the hypothalamic-pituitarythyrotrophs axis yielded conflicting results, due in part to inability to control for the effect of variable free thyroid hormone levels. We studied the effect of age and sex on TSH levels in patients with severe primary hypothyroidism who have essentially undetectable plasma thyroid hormone levels. The TSH levels were measured in 116 thyroid cancer patients four weeks after the withdrawal of thyroxine therapy in preparation for radioiodine scan/treatment. All patients had a TSH ≥30 mU/L (normal = 0.2-5) and a free T 4 <6 pmol/L (normal = 10-25). Thirty males and 86 females with a mean age (± SD) of 40 ± 16 (range 6-89 years) were studied on up to four hypothyroid episodes, with a total of 191 episodes. The TSH level during the first hypothyroid episode correlated significantly with the TSH level during subsequent episodes (first episode versus second episode, r = 0.7, P -0.0001; first versus third episode, r = 0.6, P = 0.03). There was a significant negative correlation between age and TSH level (r = -0.24, P = 0.0009) that persisted when only the first hypothyroid episode was considered (r = -0.23, P = 0.01), or when only males (r = -0.32, P = 0.02) or only females (r = -0.23, P = 0.005) were considered. Means of TSH levels in males and females were not significantly different (130 versus 114 mU/L, respectively; P = 0.28). We conclude that age but not sex may modulate the sensitivity/responsiveness of the hypothalamic-pituitary thyrotroph axis to primary hypothyroidism. Ann Saudi Med 1995;15(6):575-578. MM Hammami, B Al-Saihati, S Al-Ahmari, Influence of Age and Sex in Modulating TSH Level in Primary Hypothyroidism. 1995; 15(6): 575-578 An age-related diminution in thyrotrophs function has been found by most, but not all, investigators. In response to an injection of a bolus of thyrotropin-releasing hormone (TRH), a decrease in thyroid-stimulating hormone (TSH) release was shown in elderly males and females, 1-3 in elderly males, 4 in elderly females, 5 and in elderly males but not in elderly females. [6][7][8][9][10] Further, the expected increase in TSH level in response to the inhibition of T 4 deiodination by oral iopanoic acid was not observed in healthy elderly volunteers.11 However, TSH response to a four-hour infusion of TRH was similar in the elderly compared to young male volunteers, although there was a small but significant increase in basal TSH concentration in the elderly. 12The effect of sex on thyrotroph function is even more controversial. Significantly lower TSH response to TRH in young males compared to young females was found in some studies, 8,13,14 but not in others. 6,7,10,15 On the other hand, significantly diminished TSH response to TRH was found in elderly males compared to elderly females. 16,17 A diminished TSH response to TRH could be due to: 1) decreased thyrotrophs capacity to secrete TSH (or decreased thyrotrophs sensitivity to TRH), and/or 2) increased sensitivity of...

Chronic hypothyroidism is known to cause a significant reversible decrease in glomerular filtration rate (GFR). However, the effect on GFR of acute hypothyroidism, routinely induced in thyroid cancer patients in preparation for radioiodine scan/treatment, is not known. We studied the prevalence of abnormal serum creatinine level and the degree of its increase in hypothyroid patients with thyroid cancer four weeks after the withdrawal of thyroxine therapy. Creatinine level was measured in 116 patients on 191 hypothyroid episodes and in 56/116 and 18/116 patients while euthyroid or mildly hyperthyroid respectively. Abnormal creatinine level was significantly more prevalent in the hypothyroid state (34.5% vs 4% in the euthyroid or mildly hyperthyroid states) and significantly more common in males (50% vs 29% in females), in patients ≤ 31 years old (48% vs 26% in older patients) and in patients with a TSH level >150 mU/L (55% vs 30% with TSH ≤ 150 mU/L). Analyzing data on females only or including all hypothyroid episodes did not significantly alter the results. Further, compared to patients with normal creatinine level, patients with abnormal creatinine levels were significantly younger (in the whole group, mean age 35.1 vs 42.5 years; in the subgroup of patients with a TSH level > 150 mU/L, 29.8 vs 41.4 years; in females, 28.3 vs 42.5 years) and there was a significant negative association between the presence of abnormal creatinine levels and different age groups. Compared to levels obtained in the euthyroid or mild hyperthyroid states, creatinine levels increased in the hypothyroid state on average 32% (23μM/L, P=0.0001) with 24% of patients having ≥50% increase. Elevated serum creatinine levels are rather common in thyroid cancer patients undergoing temporary withdrawal of thyroxine treatment and more so in males, younger patients or in association with higher TSH levels. Since the clearance of iodine is linearly related to GFR, our study suggests that in the setting of hypothyroidism, the bioavailability of a given dose of radioiodine may have significant individual variation. Ann Saudi Med 1995;15(4) Scan/Treatment. 1995; 15(4): 358-362 Long-standing hypothyroidism can cause significant reversible changes in renal function such as a decrease in sodium resorption in the proximal tubules, an impairment in the concentrating and diluting capacities of the distal tubules, a decrease in urinary urate excretion, and a decrease in renal blood flow and glomerular filtration rate (GFR). [1][2][3][4] In experimental animals, surgical or drug-induced hypothyroidism of a few weeks' duration has also been shown to result in a decrease in GFR. [5][6][7] However, the effect of hypothyroidism of short duration on GFR or serum creatinine level in humans has not been well documented.We retrospectively studied the prevalence of abnormally elevated serum creatinine level and the degree of its increase in patients who had undergone thyroidectomy for differentiated thyroid cancer and in whom thyroxine therapy was withheld for f...

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