James Gibney

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The syndrome of adult GH deficiency and the effects of GH replacement therapy provide a useful model with which to study the effects of the GH/IGF-I axis on exercise physiology. Measures of exercise performance including maximal oxygen uptake and ventilatory threshold are impaired in adult GH deficiency and improved by GH replacement, probably through some(More)
CONTEXT High-molecular-weight (HMW) adiponectin contributes to insulin resistance (IR), which is closely associated with the pathophysiology of polycystic ovary syndrome (PCOS). Abnormalities in adipocyte function have been identified in PCOS and potentially contribute to lower adiponectin concentrations. OBJECTIVE Our objective was to determine which(More)
CONTEXT Declarative memory largely depends upon normal functioning temporal lobes (hippocampal complex) and prefrontal cortex. Animal studies suggest abnormal hippocampal function in hypothyroidism. OBJECTIVE The aim of the study was to assess declarative memory in overt and subclinical (SCH) hypothyroid patients before and after l-T(4) (LT4) replacement(More)
Muscle is a target of growth hormone (GH) action and a major contributor to whole body metabolism. Little is known about how GH regulates metabolic processes in muscle or the extent to which muscle contributes to changes in whole body substrate metabolism during GH treatment. To identify GH-responsive genes that regulate substrate metabolism in muscle, we(More)
BACKGROUND Macroprolactin has reduced bioactivity in vivo and accumulates in the sera of some subjects, resulting in pseudo-hyperprolactinemia and consequent misdiagnosis. METHODS We have audited our experience of routine screening for macroprolactin using polyethylene glycol (PEG) precipitation over a 5-yr period in a single center. RESULTS Application(More)
BACKGROUND Macroprolactin (big big prolactin) has reduced bioactivity and is measured by immunoassays for prolactin when it accumulates in the plasma of some individuals. We applied normative data for serum prolactin after treatment of sera to remove macroprolactin to elucidate the contribution of macroprolactin to misleading diagnoses, inappropriate(More)
The long term effects of GH replacement in adult GH-deficient (GHD) patients have not yet been clarified. We studied 21 GHD adults who originally took part in a randomized, double blind, placebo-controlled trial of GH treatment in 1987. After completion of that trial, 10 patients received continuous GH replacement for the subsequent 10 yr, whereas 11 did(More)
BACKGROUND Increased serum concentrations of macroprolactin are a relatively common cause of misdiagnosis and mismanagement of hyperprolactinemic patients. METHODS We studied sera from a cohort of 42 patients whose biochemical hyperprolactinemia was explained entirely by macroprolactin. Using 5 pretreatments, polyethylene glycol (PEG), protein A (PA),(More)
OBJECTIVES Women with polycystic ovary syndrome (PCOS) are more insulin resistant and display an atherogenic lipid profile compared with normal women of similar body mass index (BMI). Insulin resistance (IR) at least partially underlies the dyslipidemia of PCOS, but it is unclear whether PCOS status per se confers additional risk. RESEARCH DESIGN AND(More)
Polycystic ovary syndrome (PCOS) is a common, chronic endocrine condition affecting young women of reproductive age. It is characterised by hyperandrogenaemia, and profound menstrual and ovulatory dysfunction with consequent sub-fertility. A clustering of metabolic aberrations is commonly associated with this condition and these include insulin resistance,(More)