PMID- 12633789
OWN - NLM
STAT- MEDLINE
DCOM- 20031014
LR  - 20190906
IS  - 8756-3282 (Print)
IS  - 1873-2763 (Linking)
VI  - 32
IP  - 2
DP  - 2003 Feb
TI  - Parathyroid hormone secretory pattern, circulating activity, and effect on bone 
      turnover in adult growth hormone deficiency.
PG  - 170-9
AB  - Adult growth hormone deficiency (AGHD) is associated with osteoporosis. Reports 
      have associated parathyroid hormone (PTH) circadian rhythm abnormalities with 
      osteoporosis. Furthermore, there is evidence of relative PTH insensitivity in 
      AGHD patients. Factors regulating PTH circadian rhythm are not fully understood. 
      There is evidence that serum phosphate is a likely determinant of PTH rhythm. The 
      aim of this study was to investigate PTH circadian rhythm and its circulating 
      activity and association with bone turnover in untreated AGHD patients compared 
      to healthy individuals. We sampled peripheral venous blood at 30-min and urine at 
      3-h intervals during the day over a 24-h period from 1400 h in 14 untreated AGHD 
      patients (7 M, 7 W; mean age, 49.5 +/- 10.7 years) and 14 age (48.6 +/- 11.4 
      years; P = NS) and gender-matched controls. Cosinor analysis was performed to 
      analyze rhythm parameters. Cross-correlational analysis was used to determine the 
      relationship between variables. Serum PTH (1-84), phosphate, total calcium, urea, 
      creatinine, albumin, type I collagen C-telopeptides (CT(x)), a bone resorption 
      marker, and procollagen type I amino-terminal propeptide (PINP), a bone formation 
      marker, were measured on all samples. Nephrogenous cyclic adenosine monophosphate 
      (NcAMP), which reflects the renal activity of PTH, was calculated from plasma and 
      urinary cAMP. Urinary calcium and phosphate were measured on all urine samples. 
      Significant circadian rhythms were observed for serum PTH, phosphate, CT(x), and 
      PINP in AGHD and healthy subjects (P < 0.001). No significant rhythm was observed 
      for serum-adjusted calcium. PTH MESOR (rhythm-adjusted mean) was significantly 
      higher (P < 0.05), whereas the MESOR values for phosphate, CT(x) (P < 0.05), and 
      PINP (P < 0.001) were lower in AGHD patients than in controls. AGHD patients had 
      significantly lower 24-h NcAMP (P < 0.001) and higher urinary calcium excretion 
      (P < 0.05). Maximum cross-correlation between PTH and phosphate (r = 0.75) was 
      observed when PTH was lagged by 1.5 h in healthy individuals, suggesting that 
      changes in phosphate precede changes in PTH concentration. PTH/CT(x) and PTH/PINP 
      showed maximum correlation when CT(x) (r = 0.68) and PINP (r = 0.71) were lagged 
      by 3 h. In AGHD patients, compared to controls the maximum correlation between 
      PTH/phosphate (r = 0.88, P = 0.007), PTH/CTx (r = 0.61, P = 0.027), and PTH/PINP 
      (r = 0.65, P = 0.028) was observed when the lag time was reduced by 1.5 h in all 
      variables, with changes in PTH and phosphate occurring at concurrent time points. 
      Our data suggest decreased end-organ sensitivity to the effects of PTH in AGHD 
      patients, resulting in a significantly lower NcAMP, low bone turnover, and higher 
      calcium excretion in the presence of significantly higher PTH concentrations. We 
      have also demonstrated that changes in serum phosphate precede those of PTH, 
      which in turn precede changes in bone resorption and formation in healthy 
      individuals. This relationship was altered in AGHD patients. These results 
      suggest a possible role for GH in regulating PTH secretion and the bone 
      remodeling process.
FAU - Ahmad, A M
AU  - Ahmad AM
AD  - Department of Diabetes and Endocrinology, Royal Liverpool University Hospital, 
      Prescot Street Liverpool, L7 8XP, UK. DRAAHMAD@Yahoo.com
FAU - Hopkins, M T
AU  - Hopkins MT
FAU - Fraser, W D
AU  - Fraser WD
FAU - Ooi, C G
AU  - Ooi CG
FAU - Durham, B H
AU  - Durham BH
FAU - Vora, J P
AU  - Vora JP
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - United States
TA  - Bone
JT  - Bone
JID - 8504048
RN  - 0 (Parathyroid Hormone)
RN  - 0 (Phosphates)
RN  - 12629-01-5 (Human Growth Hormone)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Adult
MH  - Analysis of Variance
MH  - Bone Regeneration/*physiology
MH  - Calcium/metabolism
MH  - Circadian Rhythm/*physiology
MH  - Confidence Intervals
MH  - Female
MH  - Human Growth Hormone/*deficiency/metabolism
MH  - Humans
MH  - Hypopituitarism/metabolism
MH  - Male
MH  - Middle Aged
MH  - Monte Carlo Method
MH  - Parathyroid Hormone/*metabolism/*physiology
MH  - Phosphates/metabolism
EDAT- 2003/03/14 04:00
MHDA- 2003/10/15 05:00
CRDT- 2003/03/14 04:00
PHST- 2003/03/14 04:00 [pubmed]
PHST- 2003/10/15 05:00 [medline]
PHST- 2003/03/14 04:00 [entrez]
AID - S8756328202009523 [pii]
AID - 10.1016/s8756-3282(02)00952-3 [doi]
PST - ppublish
SO  - Bone. 2003 Feb;32(2):170-9. doi: 10.1016/s8756-3282(02)00952-3.