[Haemoglobin A1c measurements when to use and when not]

Haemoglobin A1c (HbA1c) reflects the glycaemic status of the latest 2-3 month and is used in both diagnosing and monitoring diabetes. Different circumstances may lead to spurious HbA1c results as summarised in this review. HbA1c is susceptible to changes in erythrocyte turnover (e.g. anaemia) regardless of measurement method, and to analytical interference (e.g. haemoglobin variants) depending on the method. The laboratory may detect and warn of suspected analytical interference. However, if the clinical presentation and glycaemic measures are incoherent, spurious HbA1c should be suspected and fasting glucose should be measured.

Reversible Albumin-Binding GH Possesses a Potential Once-Weekly Treatment Profile in Adult Growth Hormone Deficiency

CONTEXT

NNC0195-0092 is a reversible, albumin-binding GH derivative, developed for once-weekly administration.

OBJECTIVES

The objective of the study was to evaluate safety, local tolerability, pharmacodynamics, and pharmacokinetics of multiple, once-weekly doses of NNC0195-0092, compared with daily GH.

DESIGN AND SETTING

This was a phase 1, randomized, open-label, active-controlled, multiple-dose, dose-escalation trial.

PATIENTS

Thirty-four GH-treated adult subjects (male, n = 25) with GH deficiency participated in the study.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Subjects were sequentially assigned into four cohorts of eight subjects, randomized within each cohort (3:1) to once-weekly NNC0195-0092 (n = 6) for 4 weeks (0.02, 0.04, 0.08, and 0.12 mg/kg) or daily injections of Norditropin NordiFlex (n = 2) for 4 weeks with a dose replicating the pretrial dose of somatropin. A safety assessment was performed prior to initiating treatment at the next dose level of NNC0195-0092. Daily GH treatment was discontinued 14 days before the trial start. Blood samples were drawn for assessment of safety, pharmacokinetics, pharmacodynamics (IGF-1 and IGF-binding protein-3) profiles, and immunogenicity studies.

RESULTS

Numbers of adverse events were similar at the dose levels of 0.02, 0.04, and 0.08 mg/kg NNC0195-0092 vs daily injections of Norditropin NordiFlex, whereas the number of adverse events was greater at the highest dose level of NNC0195-0092 (0.12 mg/kg). NNC0195-0092 (area under the curve[0-168h]) and peak plasma concentration) increased in a dose-dependent manner, and a dose-dependent increase in IGF-1 levels was observed. IGF-1 profiles were elevated for at least 1 week, and for the 0.02-mg/kg and 0.04-mg/kg NNC0195-0092 doses, the observed IGF-1 levels were similar to the levels for the active control group.

CONCLUSION

Four once-weekly doses of NNC0195-0092 (dose range 0.02-0.12 mg/kg) administered to adult patients with GH deficiency were well tolerated, and IGF-1 profiles were consistent with a once-weekly treatment profile. No clinically significant safety and tolerability signals causally related to NNC0195-0092 were identified, nor were any immunogenicity concerns revealed.

Patient reported outcome in posttraumatic pituitary deficiency: results from The Danish National Study on posttraumatic hypopituitarism

OBJECTIVE

Posttraumatic pituitary hormone deficiency is often suggested. The impact of these predominantly mild and often irreproducible deficiencies on outcome is less clear. The aim of the present study was to describe patient reported outcome in a national a priori unselected cohort of patients with traumatic brain injury (TBI) in relation to deficiencies identified upon pituitary assessment.

DESIGN AND METHODS

We conducted a nationwide population-based cohort study. Participants were Danish patients with a head trauma diagnosis recorded in the Danish Board of Health diagnostic code registry; 439 patients (and 124 healthy controls) underwent assessment of anterior pituitary function 2.5 years (median) after TBI. Questionnaires on health-related quality of life (QoL) (SF36, EuroQoL-5D, QoL assessment of GH deficiency in adults) and fatigue (MFI-20) were completed in parallel to pituitary assessment.

RESULTS

Patients with TBI had significant detriments in QoL. Impairment (mainly physical scales) related to pituitary deficiency, although only partially confirmed after adjustment for demographic differences. Hypogonadotropic hypogonadism related to several QoL scores. Increasing impairments were observed with declining total testosterone concentrations (men), but not free testosterone concentrations or any other hormone concentrations. Total testosterone was not independently related to impaired QoL and fatigue, after adjustment for demographics, and treatment with antidiabetics, opioids, antidepressants, and anticonvulsants.

CONCLUSIONS

Only a very limited relationship between pituitary hormone deficiencies and QoL/fatigue was demonstrated. Due to the dominating influence of concurrent comorbidities, pituitary deficiencies were not independently related to QoL/fatigue. Causality is still to be shown, and whether substitution therapy could be of additional relevance in selected patients needs to be proven.

Interaction between exogenous insulin, endogenous insulin, and glucose in type 2 diabetes patients

BACKGROUND

Little is known about the influence of exogenous insulin and actual glucose levels on the release of endogenous insulin in insulin-treated type 2 diabetes mellitus (T2DM) patients. This study investigated the interaction among serum endogenous insulin (s-EI), serum exogenous insulin aspart (s-IAsp), and blood glucose levels in an experimental short-term crossover design.

STUDY DESIGN AND METHODS

Eight T2DM patients (63.52 years old; range, 49-69 years; mean body mass index, 28.8±3.8 kg/m(2)) were randomized to treatment with individual fixed doses of insulin aspart (0.5-1.5 IU/h) as a continuous subcutaneous insulin infusion (CSII) during a 10-h period on two occasions with different duration of hyperglycemia: (1) transient hyperglycemia for 2 h (visit TH) and (2) continuous hyperglycemia for 12 h (visit CH).

RESULTS

During steady state the variances of plasma glucose (p-glucose), s-IAsp, and s-EI were equal within visit TH and within visit CH, but variances were significantly higher during visit CH compared with visit TH. The s-IAsp reached lower levels at visit CH compared with visit TH (test for slope=1, P=0.005). The s-EI depended on p-glucose in a nonlinear fashion during the first 100 min of both visits when s-IAsp was undetectable (adjusted R(2)=0.9). A complex but statistically significant interaction among s-IAsp, s-EI, p-glucose, and patients was observed during measurable s-IAsp levels (adjusted R(2)=0.70).

CONCLUSIONS

Endogenous and exogenous insulin showed higher variation during continuous hyperglycemia. Significantly lower levels of exogenous insulin were observed following CSII during continuous hyperglycemia compared with transient hyperglycemia. Endogenous insulin levels could in a complex way be explained by an individual interaction among p-glucose and serum exogenous insulin, if present.

Circadian variation in the pharmacokinetics of steady state continuous subcutaneous infusion of growth hormone in adult growth hormone deficient patients

BACKGROUND

Previous studies in growth hormone (GH)-deficient (GHD) patients have indicated a possible diurnal variation in the pharmacokinetics (PK) of GH after subcutaneous (sc) GH administration. Thus, higher GH levels were observed during the night with continuous sc infusion, and increased GH bioavailability was reported following daily sc injections in the evening compared to morning.

OBJECTIVE

The aim was to study whether diurnal variability in the PK of sc administered exogenous GH can be reproduced under standard conditions for all study participants, e.g. supine rest.

DESIGN AND METHODS

Eight male GHD patients (59.8 ± 8 years, body mass index 29.7 ± 4.9 kg/m(2)) received a continuous sc infusion of GH (3mg/24h) for 60 h on two different occasions. Diurnal variation in PK of GH was studied during steady state in the last 24h of the infusion period.

RESULTS

Median GH levels were higher at night time (23:00 h-07:00 h) than during the day (10:00 h-18:00 h) for visit 1 [5.1 (4.5-7.2 ng/ml/0.5h) vs. 4.6 (3.7-5.7 ng/ml/0.5h); p<0.05], and reproducible results of diurnal GH variation were obtained during visit 2 [5.7 (4.6-7.4) ng/ml/0.5h vs. 4.6 (3.8-6.0) ng/ml/0.5h, p<0.05]. Reproducible results between days 1 and 2 were also obtained during 08:30 h-20:30 h and 20:30 h-08:30 h, respectively.

CONCLUSIONS

Previous findings of higher nocturnal GH levels were confirmed during steady state continuous sc GH infusion under standard conditions. The underlying mechanisms, e.g. whether GH absorption, distribution or elimination is primarily affected need to be further elucidated.