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Hypopituitarism Evolution of anterior pituitary hormone deficiencies GH- FSH/LH vs ACTH – TSH – Prolactin if pathology tumour pressure/surgery/radiation (prolactin ) Implication – ignoring genetic defects Isolated deficit – “only” seen in case of GH If TSH/Prolactin deficient =MPHD Note “meaning” if normal TSH/low FT4 on screening investigation Case History • 50 year old freelance journalist • Diagnosed as having nasopharyngeal ca • Surgery & XRT Oct ‘99 • 3000cGy in 15 fractions (2 courses) And then? • Jan 02 - GP found Na 122 - kept under review by oncologists • Nov 02 - abnormal TFTs - started Thyroxine 50mcg increased to 100mcg • Feb 03 - patient felt worse - still tired, feeling cold, aches & pains, lightheaded, loss of balance • May 03 - referred to an endocrinologist Results Na nmol/L TSH mU/L T4 pmol/L Jan 02 Feb 02 Mar 02 Nov 02 Nov 02 124* 124* 127* 4.21* 3.24 3.60* 3.89* 59 61 8* (50-150) (50-150) (9-26) 9 (9-26) What do the TFTs suggest? SECONDARY HYPOTHYROIDISM What is the patient’s low sodium due to? • SST - 0 min - Cortisol 57nmol/L* - 30 min - Cortisol 197nmol/L* ACTH DEFICIENT Why did thyroxine exacerbate his symptoms? • Thyroxine introduced before hydrocortisone in cortisol deficiency can lead to acute cortisol deficiency **POTENTIALLY FATAL** • Consider cortisol deficiency – in a patient who has received a large dose of radiation particularly if • sodium • TSH deficient • symptoms worsen with thyroxine therapy Evolution of anterior pituitary hormone deficiencies Isolated deficiencies of anterior pituitary hormones due to pathologies other than genetic – do exist! If present – may point to underlying pathology Isolated gonadotrophin deficiency-Haemochromatosis Isolated ACTH deficiency -Lymphocytic hypophysitis Timing of onset of hypopituitarism • Childhood GHD - growth FSH/LH – puberty • Adult Normal height/secondary sex characteristics Diabetes Insipidus Implication • Site of lesion is hypothalamic/ high stalk • Pathology of lesion much more likely to be cranopharyngioma vs pituitary adenoma • Presence of DI provides no information about anterior pituitary function except that ACTH status must be normal for DI to be manifested Hypopituitarism Causes • Pituitary Adenoma – Functioning – Non-Functioning • Pituitary Surgery • Pituitary Radiotherapy – Conventional – Stereotactic • Medical Therapy – DA drugs – Pegvisomant – Anti-adrenal drugs Hypopituitarism Non-adenomatous causes • Intracranial tumours • Sheehan’s syndrome – Craniopharyngiomas • Pituitary apoplexy – Meningioma • TBI – Glioma • Empty Sella syndrome – Chordoma • Lymphocytic hypophysitis – Metastasis-breast cancer • Genetic diseases • Non-pituitary radiotherapy • Infiltrative disorders Investigation for Hypopituitarism • Gonadotrophin status – FSH,LH,T/E2 – GnRH test x • TSH – TSH, FT4 – TRH test x • Prolactin – Prolactin How is ACTH D diagnosed? • UK SoE Survey 598 Clinical Members 81 Respondents ITT SST Glucagon 9.00am Cortisol (>400 nmol/L) No Tests (NoT) Reynolds et al, Clin End (2006) ITT SST NoT Glucagon 9C 31% 44% - 2.5% 2.5% XRT 7% 65% - 4% 18% Non – XRT 9% 36% 29% - 18% Definitive testing of HPA Axis Post- Surgery Long term Assessment Reynolds et al, Clin End (2006) SST 93.8% - 250 µg 4.7% - 1µg IV vs IM – (50-50) Interpretation of Results • 67% - 30 min cortisol • 17% - 60 min cortisol • 7 % - increment cortisol • 9% - combinations Reynolds et al, Clin End (2006) Interpretation of Results SST • Adequate peak cortisol response 250 – 650 nmol/l • Peak cortisol >550nmol/l at 30 min (51%) ITT • Adequate peak cortisol response 400 – 600 nmol/l • Peak cortisol > 550nmol/l (47%) Reynolds et al, Clin End (2006) Glucorticoid Replacement • • • • • If patients symptomless but had failed chosen test of HPA axis 28% - still treated with glucocorticoid replacement 38% - retested before treatment 24% - recommended glucocorticoid cover when unwell or ‘stressed’ 6% recommend patient carry steroid card 4% - individual basis Reynolds et al, Clin End (2006) Glucocorticoid replacement Hydrocortisone • 20mg/day (56%) • 67% - 10/5/5 • Higher doses by 25% • Lower doses by 13% General Trends • More SST – Less ITT • Lower replacement doses of HC Reynolds et al, Clin End (2006) Investigation for Hypopituitarism • ACTH – Morning Cortisol (<100 – 300nmol/l) – ITT/ Glucagon/Synacthen • GH Status – Provocative GH tests, IGF-1 – IGFBP-3/ALSx Severe Adult GHD (ITT) 8 P <0.0001 GH Peak ( m g/L) 6 4 2 0 GHD0 GHD1 GHD2 GHD3 Toogood et al. Clin. Endocrinol. 1994 How many tests to diagnose GHD in severe adult GHD 103 patients - documented or potential HP disease - normal BMI - ITT & AST 35 controls Lissett et al (1999) Pituitary Hormone Deficits GHD O 1 2 3 Controls Patient numbers 69 15 6 13 35 7.5 6.8 2.4 2.4 0.75 1.0 0.5 0.5 65 32 76.8 66.6 83.3 92.3 100 Median Peak GH (mU/l) - ITT - AST Concordance Between tests (%) Lissett et al (1999) Magnitude of difference between each individuals GH response to ITT and AST plotted against mean GH value 100 Spearmans Rank correlation = 0.88, P <0.0001 10 Difference between ITT and AST (mU/l) 1 0.1 0.1 1 10 100 Mean GH response (mU/l) Lissett et al (1999) Implications Adults • GHDO/GHD1 patients require 2 GH stimulation tests vs only 1 required in GHD2/GHD3 patients Specificity of GH stimulation test The debate about 2 tests vs. 1 test also assumes that the information gained from each of the tests is the same and independent of the nature of the pathophysiology Study Objectives To investigate the role of the GHRH + AST in the diagnosis of radiation-induced GHD in comparison with the “Gold Standard”, the ITT. (Darzy et al, 2003) Subjects and Methods * 58 adult patients (37 males), age 22.9(16-53.7)yr. * All received cranial irradiation for non-pituitary brain tumour or leukaemia ( age 1.3-49 years ). * Endocrine deficit other than GH present in 11 patients * All patients had hormone replacement optimised before testing (Darzy et al, 2003) 33 sex and age matched control group. * GHRH+AST and ITT in all normals and patients * Patients were tested 11.8 (1.5 – 32.8) yr post irradiation. * Tests on two separate mornings. (Darzy et al, 2003) 120 N = normal controls P = patients Peak GH responses (µg / L). 100 80 N 60 55 40 N 23.8 20 P 14.5 P < 0.05 P < 0.05 0 P 4.8 -20 GHRH+AST ITT GHRH+AST ITT (Darzy et al, 2003) The peak GH responses to the ITT and time after irradiation Peak GH responses to the ITT (µg / L) 60 Normals n = 33 40 20 0 Normal < 6yr 6-12yr 12-18yr >18yr (Darzy et al, 2003) Peak GH responses to the combined GHRH + AST (µg / L) The peak GH responses to the GHRH + AST and time after irradiation 120 Normals 100 < 6 yr 80 60 12 - 18 6 - 12 > 18 40 20 0 Time interval since irradiation (yr) (Darzy et al, 2003) The discordancy ratio and time after irradiation 30 20 10 0 Median BED 58.3 Normals <6yr 58.3 48.82 54.4 6-12yr 12-18yr >18yr Time interval since irradiation (Darzy et al, 2003) Patients and Methods • Centrally measured IGF-I data from the KIMS European database were analysed • Patients with adult onset GHD and 2 or more anterior pituitary hormone deficits were included • Patients with childhood onset GHD and cured acromegaly were excluded Patients and Methods • Baseline IGF-I measurements from; - 376 females (median age 48, range 21 to 77 years) and - 434 males (median age 52, range 21 to 80 years) • The cohort was stratified into six gender based age ranges • IGF-I & IGF-I SDS were determined for each group Percentage of patients with severe adult-onset GHD with IGF-I levels within the normal age related range Females Age Range (Years) 21 - 30 31 - 40 41 - 50 51 - 60 61 - 70 71 - 80 Number per group 24 74 123 93 51 11 % 8.3 31.1 41.5 49.5 52.9 54.5 Percentage of patients with severe adult-onset GHD with IGF-I levels within the normal age related range Males Age Range (Years) Number % per group 21-30 30 26.7 31-40 62 62.9 41-50 102 61.8 51-60 149 73.1 61-70 75 60.0 71-80 16 75.0 Box and whisker plots representing IGF-I SDS in females with AO-GHD 4 2 0 -2 -4 IGF-I SDS -6 -8 -10 21-30 31-40 41-50 51-60 61-70 Age Range (Years) 71-80 Box and whisker plots representing IGFI SDS in males with AO-GHD 4 2 0 -2 IGF-I SDS -4 -6 -8 21-30 31-40 41-50 51-60 61-70 Age Range (Years) 71-80 Summary • These data demonstrate; – a large overlap of IGF-I SDS between normal and severely GHD adults – overlap of IGF-I between normal and severely GHD adults is predominantly limited to the lower half of the normal range GHD2/GHD3 = 1 GH Provocative test vs. IGF-1 GHD0/GHD1 = 2 GH Provocative tests vs. 1GH Provocative test plus IGF-1 GH stimulation tests • ITT/Arginine/Glucagon • Arginine + GHRH • GHRH + GHRP • Clonidine? GHRH? – No – Age – BMI/Fat Mass – Availability Diabetes Insipidus • 24 hour urine output > 3 litres • 8 hour fluid deprivation test Radiology – MRI Scan • Absent PP high signal • Microadenoma vs Macrodenoma – Risk of hypopituitarism • Stalk interruption • Type and site of lesion • Evolution Pituitary hormone deficiencies • ACTH – Hydrocortisone (tds) • FSH/LH – Cortisol profiles – Sex Steriods – Emergency advice – Fertility-Gonadotrophins Treatment • TSH – T4 (threshold) • DI – Desmopressin • GH – GH Partial ACTH D - Glucorticoid replacement 10 males – partial ACTH D • Base line plasma cortisol > 200nmol/l • Peak stimulated cortisol<500nmol/l 10 matched controls Cross-over randomised protocol – HC 10mgs BD vs 5 mgs BD vs no treatment Agha et al Clin End.2004 Age (years) BMI (kg/m2) CBG (mg/l) Baseline cortisol Peak stimulated cortisol Pts, n=10 Controls, n=10 P-value 43.9±10.8 31.1±4.5 41.7±7.1 273.9±61.8 432.9±58.9 38.9±12.2 30.8±4.3 44.9±4.6 357.3±84.4 0.34 0.88 0.25 0.021 Results presented as mean±SD. BMI, body mass index; CBG, corticosteroid-binding globulin Agha et al 2004 FD HD NT Control 500 Cortisol 400 300 200 100 0 2 4 6 8 10 Time Agha et al 2004 Long-acting GH preparation in patients with GHD Open-label randomised study • 135 patents – 32 weeks • Depot GH vs Daily GH vs no treatment • Dose GH titrated to maintain IGF-1 within age-adjusted normal range Hoffman et al (2005) Adverse events 1- death - “Adrenal crisis” On Depot GH Two other serious and three non-serious cases of “adrenal crisis or insufficiency” • 3 cases on daily GH vs 3 cases – depot GH • All had ACTH deficiency and were on glucocorticoid replacement Hoffman et al (2002) Risk of Cortisol deficiency on GH replacement • Ignorance – glucocorticoid dosage not during intercurrent illness • Influence of Gh-IGF-1 axis on II β HSD driving cortisol-cortisone shuttle in favour of “cortisone” • GH ↓ Cortisol-B-G At Risk • Steroid card/Emergency Pack • Borderline ACTH D not receiving glucocorticoid replacement (Giavoli et al,2004) • Sub-optimal glucocorticoid replacement GH replacement and thyroid function in adult GHD patients 66 adult GHD patients • 17 euthyroid/49 hypothyroid on T4 • 6 month GH replacement study – 2 dose regimes • Normalisation of IGF-1 in 67% patients – independent of GH dose • Significant ↓in FT4 and reverse T3 levels • No change in TSH, FT3, thyroxine BG levels Porretti et al (2002) Porretti et al (2002) • 8/17 euthyroid subjects and 9/49 central hypothyroid patients showed FT4 levels below normal range at end of study despite adequate substitution at baseline. Altogether 17/66 patients worsened thyroid function * Monitor thyroid – function carefully