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Our case illustrates coexistence of hypopituitarism and clinically significant autoimmune thyroid disease. The presence of hypopituitarism does not preclude the development of autoimmune thyrotoxicosis.

Objective Diagnosis of primary hyperaldosteronism in pregnancy is complicated due to lack of reference ranges for aldosterone, renin and aldosterone-to-renin ratio. We have endeavoured to establish third-trimester reference ranges for the above-mentioned parameters. Design & Patients We performed postural tests for aldosterone and renin (chemiluminescence immunoassay Liason® DiaSorin Inc., Italy) in 70 healthy pregnant women (age 30.53±4.51 years), at 32.38±4.25 weeks of gestation and in 22 non-pregnant healthy women (age 33.08±8.72 years). Results Aldosterone reference ranges were 6.51–73.97 ng/dl and 12.33–86.38 ng/dl, for supine and upright positions, respectively and that for renin were 6.25–59.36 µIU/ml and 11.12–82.55 µIU/ml, respectively. Aldosterone and renin concentrations were higher in an upright position (p=0.000459 and p=0.00011, respectively). In contrast, aldosterone-to-renin ratio was not affected by posture (i. e. 0.497–3.084 ng/dl/µIU/ml versus 0.457–3.06 ng/dl/µIU/ml, p=0.12), but was higher (p=0.00081) than in non-pregnant controls. In comparison to manufacturer-provided non-pregnant reference range, supine aldosterone concentrations increased by 556% (lower cut-off) and 313% (upper cut-off), while upright aldosterone concentrations increased by 558% (lower cut-off) and 244% (upper cut-off). The reference range for supine renin concentrations increased by 223% (lower cut-off) and 48.7% (upper cut-off), while upright renin concentrations increased by 253% (lower cut-off) and 79% (upper cut-off). Conclusions There is an upward shift in aldosterone and renin reference ranges in the third-trimester of pregnancy accompanied by an increase in an aldosterone-to-renin ratio, that is not influenced by posture. It remains to be established whether the aldosterone-to-renin ratio may be used as a screening tool for primary hyperaldosteronism in pregnancy.

BackgroundRaised parathormone (PTH) and normal calcium concentrations can be observed both in normocalcemic primary hyperparathyroidism (nPHPT) and in secondary hyperparathyroidism, e.g. due to vitamin D deficiency. We assessed the impact of season on the validity of diagnosis of nPHPT in terms of screening investigations to be performed in the primary care settings.Material and methodsOn two occasions (March/April & September/October) we measured vitamin D (25OHD), PTH and total calcium in 125 healthy subjects, age range 6-50, not taking any vitamin D supplements.ResultsIn autumn there was an increase in 25OHD concentrations (from 18.1 ± 7.37ng/ml to 24.58 ± 7.72ng/ml, p<0.0001), a decline in PTH from 44.40 ± 17.76pg/ml to 36.63 ± 14.84pg/ml, p<0.001), without change in calcium levels. Only 45 subjects (36%) were vitamin D sufficient (25OHD>20/ml) in spring versus 83 (66.4%) in autumn, p<0.001. Elevated PTH concentrations were noted in 10 subjects in spring (8%) and in six subjects (4.8%) (p<0.05) in autumn. In spring, however, eight out of ten of these subjects (80%) had 25OHD<20 ng/ml, versus one in six (16.7%) in autumn (p<0.01). Normalization of PTH was observed in seven out ten subjects (70%), and all of them had 25-OHD<20 ng/ml in spring.ConclusionsIn spring elevated PTH concentrations in the setting of normocalcemia are more likely to be caused by 25OHD deficiency rather by nPHPT. In contrast, in autumn, increased PTH concentrations are more likely to reflect nPHPT. We postulate that screening for nPHPT should be done in 25OHD replete subjects, i.e. in autumn rather than in spring.