Rationale. Cystic fibrosis related diabetes (CFRD) is the most common comorbidity in patients with CF. In spite of increased screening, diagnosis, and treatment of CFRD, the mortality rate in patients with CFRD still far exceeds the mortality rate in those without CFRD. Guidelines suggest that screening for CFRD be performed annually using the 2-hour 75-gram oral glucose tolerance test (OGTT). Adherence to recommended screening has been poor, with only approximately one-quarter of adults with CF undergoing OGTT in 2014. Use of continuous glucose monitoring (CGM) for diagnosis may become an alternative. Objectives. Our objective was to determine whether abnormal CGM predicts subsequent development of CFRD, lung function, and body mass index (BMI) decline and increased rate of CF pulmonary exacerbations in adults with CF. Methods. In a prospective single center pilot trial from September 2009 to September 2010, 21 adult patients due for routine OGTT were recruited to complete simultaneous 3-day CGM and 2-hour 75 gram OGTT. Subsequently, clinical information was reviewed from 2008 to 2015. Conclusions. There was a moderate correlation between interpreted results of 2-hour OGTT and CGM (p = 0.03); CGM indicated a greater level of glucose impairment than OGTT. Glucose >200 mg/dL by CGM predicted development of CFRD (p = 0.0002).

RationaleAirway inflammation is central to cystic fibrosis (CF) pathophysiology. Pre-clinical models have shown that phosphodiesterase inhibitors (PDEi) like sildenafil have anti-inflammatory activity. PDEi have not been studied in CF subjects.ObjectivesWe evaluated the pharmacokinetics, tolerability, and safety of sildenafil in subjects with CF. Sputum biomarkers were used to explore efficacy.MethodsAn open-label pilot study of oral sildenafil administration was conducted in adults with mild to moderate CF lung disease. Subjects received oral sildenafil 20 or 40 mg p.o. t.i.d. for 6 weeks.Measurements and main resultsTwenty subjects completed the study. Estimated elimination rate constants were statistically different in subjects with CF compared to previously published non-CF subjects. Side effects were generally mild. There were no drug-related serious adverse events. Sputum neutrophil elastase activity decreased.ConclusionsSubjects with CF may eliminate sildenafil at a faster rate than non-CF subjects. Sildenafil administration was safe in subjects with CF and decreased sputum elastase activity. Sildenafil warrants further study as an anti-inflammatory in CF.

BACKGROUND:Acute pulmonary exacerbations accelerate pulmonary decline in cystic fibrosis (CF). There is a critical need for better predictors of treatment response.OBJECTIVE:To test whether expression of a panel of leucocyte genes directly measured from whole blood predicts reductions in sputum bacterial density.METHODS:A previously validated 10-gene peripheral blood mononuclear cell (PBMC) signature was prospectively tested in PBMC and whole blood leucocyte RNA isolated from adult subjects with CF at the beginning and end of treatment for an acute pulmonary exacerbation. Gene expression was simultaneously quantified from PBMCs and whole blood RNA using real-time PCR amplification. Test characteristics including sensitivity, specificity, positive and negative predictive values were calculated and receiver operating characteristic curves determined the best cut-off to diagnose a microbiological response. The findings were then validated in a smaller independent sample.RESULTS:Whole blood transcript measurements are more accurate than forced expiratory volume in 1 s (FEV(1)) or C reactive protein (CRP) alone in identifying reduction of airway infection. When added to FEV(1), the whole blood gene panel improved diagnostic accuracy from 64% to 82%. The specificity of the test to detect reduced infection was 88% and the positive predictive value for the presence of persistent infection was 86%. The area under the curve for detecting treatment response was 0.81. Six genes were the most significant predictors for identifying reduction in airway bacterial load beyond FEV(1) or CRP alone. The high specificity of the test was replicated in the validation cohort.CONCLUSIONS:The addition of blood leucocyte gene expression to FEV(1) and CRP enhances specificity in predicting reduced pulmonary infection and may bolster the assessment of CF treatment outcomes.

Circulating GH, IGF-I, IGFBP-3, and sex steroid concentrations decrease with age. GH or sex steroid treatment increases IGFBP-3, but little is known regarding the effects of these hormones on other IGFBPs. We assessed the effects of 26 wk of administration of GH, sex steroids, or GH + sex steroids on AM levels of IGF-I, IGFBPs 1-5, insulin, glucose, and osteocalcin and 2-h urinary excretion of deoxypyridinolline (DPD) cross-links in 53 women and 71 men aged 65-88 yr. Before treatment, in women and men, IGF-I was directly related to IGFBP-3 (P < 0.001 and P < 0.0001) and IGFBP-1 to IGFBP-2 (P = 0.0001). In women, IGFBP-1 was inversely related to insulin (P < 0.0005) and glucose (P < 0.005) and IGFBP-4 to osteocalcin (P < 0.01). IGFBP-4 and IGFBP-5 were not significantly related to DPD cross-links. GH and/or sex steroid increased IGF-I levels in both sexes, with higher concentrations in men (P < 0.001). In women, the IGF-I increment after GH was attenuated by hormone replacement therapy (HRT) coadministration (P < 0.05). Hormone administration also increased IGFBP-3. IGFBP-1 was unaffected by GH + sex steroids, whereas GH decreased IGFBP-2 by 15% in men (P < 0.05). Hormone administration did not change IGFBP-4, whereas in men IGFBP-5 increased by 20% after GH (P < 0.05) and 56% after GH + testosterone (P = 0.0003). These data demonstrate sexually dimorphic IGFBP responses to GH. Additionally, HRT attenuated or prevented GH-mediated increases in IGF-I and IGFBP-3. Whether GH and/or sex steroid administration alters local tissue production of IGFBPs and whether the latter influence autocrine or paracrine actions of IGF-I remain to be determined.

CONTEXT:Hormone administration to elderly individuals can increase lean body mass (LBM) and decrease fat, but interactive effects of growth hormone (GH) and sex steroids and their influence on strength and endurance are unknown.OBJECTIVE:To evaluate the effects of recombinant human GH and/or sex steroids on body composition, strength, endurance, and adverse outcomes in aged persons.DESIGN, SETTING, AND PARTICIPANTS:A 26-week randomized, double-blind, placebo-controlled parallel-group trial in healthy, ambulatory, community-dwelling US women (n = 57) and men (n = 74) aged 65 to 88 years recruited between June 1992 and July 1998.INTERVENTIONS:Participants were randomized to receive GH (starting dose, 30 micro g/kg, reduced to 20 micro g/kg, subcutaneously 3 times/wk) + sex steroids (women: transdermal estradiol, 100 micro g/d, plus oral medroxyprogesterone acetate, 10 mg/d, during the last 10 days of each 28-day cycle [HRT]; men: testosterone enanthate, biweekly intramuscular injections of 100 mg) (n = 35); GH + placebo sex steroid (n = 30); sex steroid + placebo GH (n = 35); or placebo GH + placebo sex steroid (n = 31) in a 2 x 2 factorial design.MAIN OUTCOME MEASURES:Lean body mass, fat mass, muscle strength, maximum oxygen uptake (VO(2)max) during treadmill test, and adverse effects.RESULTS:In women, LBM increased by 0.4 kg with placebo, 1.2 kg with HRT (P =.09), 1.0 kg with GH (P =.001), and 2.1 kg with GH + HRT (P<.001). Fat mass decreased significantly in the GH and GH + HRT groups. In men, LBM increased by 0.1 kg with placebo, 1.4 kg with testosterone (P =.06), 3.1 kg with GH (P<.001), and 4.3 kg with GH + testosterone (P<.001). Fat mass decreased significantly with GH and GH + testosterone. Women's strength decreased in the placebo group and increased nonsignificantly with HRT (P =.09), GH (P =.29), and GH + HRT (P =.14). Men's strength also did not increase significantly except for a marginally significant increase of 13.5 kg with GH + testosterone (P =.05). Women's VO(2)max declined by 0.4 mL/min/kg in the placebo and HRT groups but increased with GH (P =.07) and GH + HRT (P =.06). Men's VO(2)max declined by 1.2 mL/min/kg with placebo and by 0.4 mL/min/kg with testosterone (P =.49) but increased with GH (P =.11) and with GH + testosterone (P<.001). Changes in strength (r = 0.355; P<.001) and in VO(2)max (r = 0.320; P =.002) were directly related to changes in LBM. Edema was significantly more common in women taking GH (39% vs 0%) and GH + HRT (38% vs 0%). Carpal tunnel symptoms were more common in men taking GH + testosterone (32% vs 0%) and arthralgias were more common in men taking GH (41% vs 0%). Diabetes or glucose intolerance occurred in 18 GH-treated men vs 7 not receiving GH (P =.006).CONCLUSIONS:In this study, GH with or without sex steroids in healthy, aged women and men increased LBM and decreased fat mass. Sex steroid + GH increased muscle strength marginally and VO( 2)max in men, but women had no significant change in strength or cardiovascular endurance. Because adverse effects were frequent (importantly, diabetes and glucose intolerance), GH interventions in the elderly should be confined to controlled studies.

Aging is associated with reduced GH, IGF-I, and sex steroid axis activity and with increased abdominal fat. We employed a randomized, double-masked, placebo-controlled, noncross-over design to study the effects of 6 months of administration of GH alone (20 μg/kg BW), sex hormone alone (hormone replacement therapy in women, testosterone enanthate in men), or GH + sex hormone on total abdominal area, abdominal sc fat, and visceral fat in 110 healthy women (n= 46) and men (n = 64), 65–88 yr old (mean, 72 yr). GH administration increased IGF-I levels in women (P = 0.05) and men (P = 0.0001), with the increment in IGF-I levels being higher in men (P = 0.05). Sex steroid administration increased levels of estrogen and testosterone in women and men, respectively (P = 0.05). In women, neither GH, hormone replacement therapy, nor GH + hormone replacement therapy altered total abdominal area, sc fat, or visceral fat significantly. In contrast, in men, administration of GH and GH + testosterone enanthate decreased total abdominal area by 3.9% and 3.8%, respectively, within group and vs. placebo (P = 0.05). Within-group comparisons revealed that sc fat decreased by 10% (P = 0.01) after GH, and by 14% (P = 0.0005) after GH + testosterone enanthate. Compared with placebo, sc fat decreased by 14% (P = 0.05) after GH, by 7% (P= 0.05) after testosterone enanthate, and by 16% (P = 0.0005) after GH + testosterone enanthate. Compared with placebo, visceral fat did not decrease significantly after administration of GH, testosterone enanthate, or GH + testosterone enanthate. These data suggest that in healthy older individuals, GH and/or sex hormone administration elicits a sexually dimorphic response on sc abdominal fat. The generally proportionate reductions we observed in sc and visceral fat, after 6 months of GH administration in healthy aged men, contrast with the disproportionate reduction of visceral fat reported after a similar period of GH treatment of nonelderly GH deficient men and women. Whether longer term administration of GH or testosterone enanthate, alone or in combination, will reduce abdominal fat distribution-related cardiovascular risk in healthy older men remains to be elucidated.

We studied 130 healthy aged women (n = 57) and men (n = 73), age 65-88 yr, with age-related reductions in insulin-like growth factor I and gonadal steroid levels to assess the interrelationships between cortisol and growth hormone (GH) secretion and whether these relationships differ by sex. Blood was sampled every 20 min from 8:00 PM to 8:00 AM; cortisol was measured by RIA and GH by immunoradiometric assay, followed by deconvolution analyses of hormone secretory parameters and assessment of approximate entropy (ApEn) and cross-ApEn. Cortisol mass/burst, cortisol production rate, and mean and integrated serum cortisol concentrations (P < 0.0005), and overnight basal GH secretion (P < 0.05), were elevated in women vs. men. Integrated cortisol concentrations were directly related to most measures of GH secretion in women (P < 0.01) and with mean and integrated GH concentrations in men (P < 0.05). Integrated GH concentrations were directly related to mean and integrated cortisol levels in women (P < 0.005) and men (P < 0.05), with no sex differences. There were no sex differences in cortisol or GH ApEn values; however, the cross-ApEn score was greater in women (P < 0.05), indicating reduced GH-cortisol pattern synchrony in aged women vs. men. There were no significant relationships of integrated cortisol secretion with GH ApEn, or vice versa, in either sex. Thus postmenopausal women appear to maintain elevated cortisol production in patterns that are relatively uncoupled from those of GH, whereas mean hormone outputs remain correlated.