Biomedical subjects

M A Birkett

Publications and source records attributed to M A Birkett.

7 recordsLinked to original sources

PubMed1998

Postprandial insulin lispro. A new therapeutic option for type 1 diabetic patients.

OBJECTIVE: For intensified insulin therapy of type 1 diabetes, bolus injection of regular human insulin 30-15 min before a meal is currently recommended. This randomized study is aimed to determine whether insulin lispro (LIS), a new insulin analog with a rapid onset of action, can provide comparable blood glucose (BG) control by injection after the meal. RESEARCH DESIGN AND METHODS: Eighteen type 1 diabetic subjects injected regular insulin (REG) at 40, 20, or 0 min before or LIS at 20 or 0 min before or 15 min after the start of a standardized test meal. BG excursions and area under the curve of BG excursions (AUC) at the six visits were compared by analysis of variance. Hypoglycemic events (BG < or = 2.78 mmol/l) were evaluated in relation to the achieved postprandial BG control. RESULTS: Mean AUC values were 2.00, 2.55, and 3.33 mmol.h.l-1 for REG given 40, 20, and 0 min before the test meal, respectively, and -2.19, -2.15, and 1.98 mmol.h.l-1 for LIS given 20 and 0 min before and 15 min after the start of the test meal, respectively. LIS injected 20 min (-20) or immediately (0) before the meal was significantly more effective in controlling postprandial BG excursion (P < 0.001) than any REG treatment. Postprandial injection of LIS (15) did not compromise postprandial BG control and resulted in less hypoglycemia. REG -40 and LIS -20 were associated with early hypoglycemia, but other hypoglycemic events were equally distributed among groups. CONCLUSIONS: The optimal time for bolus insulin injection was 20 min before the meal for REG and immediately before the meal for LIS. LIS injected immediately after a standard meal provided postprandial BG control at least as good as REG injected from 40 to 0 min before the meal. Postprandial injection of LIS is an attractive new therapeutic option.

Adult↗

PubMed1997

The safety profile of GH replacement therapy in adults.

OBJECTIVE: The benefits of GH replacement in GH-deficient adult patients are becoming accepted but the safety profile continues to be defined. The GH deficiency in adults may have arisen i either childhood or during adult life and these two groups differ with regard to history of disease. The aid of the present report was to study differences in safety profile between these two groups during long-term replacement therapy with recombinant human GH (hGH). Possible factors which placed a patient at risk of experiencing an adverse event were also examined. PATIENTS AND DESIGN: GH-deficient adult patients were randomized into two study protocols, differing only in age of onset of the GH deficiency syndrome. There were 98 patients with adult-onset and 67 patients with childhood-onset GH deficiency. Each study consisted of a 6-month double-blind placebo-controlled phase followed by an open-label hGH treatment phase. Glucose tolerance, incidence of treatment-emergent adverse events and relationship to IGF status were studied throughout the 36 months of treatment. RESULTS: Human growth hormone-related adverse events were reported less commonly in childhood-onset patients compared with adult-onset patients. Adult-onset patients who continued into the open-label therapy phase reported an increased incidence of arthralgia, myalgia and paraesthesia. There were significant increases in fasting glucose with hGH therapy but values remained within the normal range. Hypertension was reported in 7.7% of adult-onset patients at 18 months of hGH, which was within the expected prevalence for the number of patients, but was not reported for any childhood-onset patients. Only in adult-onset patients were sufficient adverse events reported to enable analysis of risk factors. Patients reporting hGH-related adverse events were significantly heavier and, therefore, received more hGH. There was a significantly greater increase in IGF-I and IGFBP-3 in the first month in patients who experienced hGH-related adverse events compared with those who did not. CONCLUSION: The risks of replacement therapy with hGH in GH-deficient adults varied with pathogenesis of disease; hGH-related adverse events occurred more frequently in patients with adult-onset compared with those childhood-onset GH deficiency. In the adult-onset patients there was an increased risk of adverse events in heavier patients and those who had the greatest increases in IGF-I and IGFBP-3 at 1 month of therapy.

Adult↗

PubMed1997

Adult growth hormone (GH)-deficient patients demonstrate heterogeneity between childhood onset and adult onset before and during human GH treatment. Adult Growth Hormone Deficiency Study Group.

The onset of adult GH deficiency may be during either adulthood (AO) or childhood (CO), but potential differences have not previously been examined. In this study the baseline and GH therapy (12.5 micrograms/kg per day) data from CO (n = 74; mean age 29 yr) and AO (n = 99; mean age 44 yr) GH-deficient adult patients have been compared. The first 6 months comprised randomized, double-blind treatment with GH or placebo, then all patients were GH-treated for a further 12 months. At baseline the height, body weight, body mass index, lean body mass, and waist/hip ratio of AO patients were significantly (P < 0.001) greater than in CO patients. Serum insulin-like growth factor-I (IGF-I) levels were below normal but were lower in CO than AO patients (P < 0.001), and the correlation with IGF binding protein-3 was stronger in CO than in AO patients. Osteocalcin concentration in CO patients was above the normal range and significantly greater than in AO patients. Both groups had significant psychosocial distress, but the deviation from normality was greater in AO patients. Throughout GH therapy there was a significant increase in lean body mass and significant decrease in percent body fat and sum of skinfolds in each group. Wais/hip ratio was decreased by long-term therapy in AO but not CO patients. Total and low density lipoprotein cholesterol levels were decreased from baseline at 6 months in AO but not CO patients and high density lipoprotein cholesterol was increased in both groups throughout therapy. IGF-I and IGF binding protein-3 were increased into the normal range by GH therapy in both groups. Mean osteocalcin level in AO patients was increased at 6 months with no further change with GH therapy, whereas in CO patients there was a steep increase up to 12 months but then a sharp decrease. Nottingham Health Profile scores showed significant improvements in physical mobility and energy at 18 months of therapy in AO patients but no consistent effects in CO patients. GH-induced side effects were mainly reported by AO patients; very few CO patients reported treatment-emergent adverse events. These results demonstrate significant differences in clinical and biochemical presentation and responses to therapy of the adult GH deficiency syndrome. This is consistent with the existence of two entities, developmental (CO) and metabolic (AO), and the different functions of GH at different periods of life.

Adult↗

PubMed1997

Fluoxetine treatment of patients with major depressive disorder who failed initial treatment with sertraline.

BACKGROUND: This study was conducted to determine if patients with major depressive disorder who had previously failed treatment with one serotonin selective reuptake inhibitor (SSRI) would respond to a different SSRI. METHOD: Adult outpatients (N = 106) with DSM-III-R major depressive disorder and a history of either intolerance (N = 34) or nonresponse (N = 72) to treatment with sertraline were treated with fluoxetine (mean dose = 37.2 mg/day) in a standardized, open-label, 6-week clinical trial. Outcome was assessed at each visit using the Hamilton Rating Scale for Depression (HAM-D), the Clinical Global Impressions (CGI-Improvement and CGI-Severity) scales, and the Patient's Global Improvement (PGI) scale. RESULTS: Ninety-one patients (86%) completed the study. Sixty-seven patients (63%) responded to fluoxetine (i.e., experienced > or = 50% reduction in HAM-D28 total score at endpoint versus baseline). In addition, clinically and statistically significant improvements were noted on all measures of depressive symptoms and global functioning. There was a nonsignificant trend for patients with a history of less vigorous sertraline trials to respond more favorably to fluoxetine. Fluoxetine therapy was generally well tolerated, and there were only slight differences in adverse events reported by patients who had been intolerant to sertraline versus those who were nonresponders. CONCLUSION: These findings indicate that fluoxetine and sertraline, two widely used SSRIs, are not interchangeable. Patients who either have had trouble tolerating or have not responded to sertraline may do well on fluoxetine treatment.

1-Naphthylamine↗

PubMed1996

Is there a relationship between baseline and treatment-associated changes in [3H]-IMI platelet binding and clinical response in major depression?

A peripheral model for the central 5-HT neuron is the characterization of platelet imipramine binding. We studied an outpatient major depressive cohort who fulfilled Research Diagnostic Criteria for agitation. After a 1-week placebo lead-in, subjects were blindly randomized to either imipramine (IMI) or fluoxetine (FLU) during an 8-week, double-blind study period. Thirty-three subjects (15 IMI, 18 FLU) provided both baseline and endpoint samples for the platelet [3H]-IMI assay. Depression efficacy was comparable across the two treatments, whereas FLU was significantly more effective in reducing secondary anxiolysis (p = .023). Discontinuations due to an adverse event were significantly more frequent with IMI than FLU (p < .01). Baseline affinity (KD) was mildly predictive of change in the HAMD (r = -.22; p = .07). Whereas baseline to endpoint density (Bmax) changes (delta) were similar for IMI (183 +/- 329 fmol/mg) and FLU (196 +/- 402 fmol/mg), a statistically significant treatment difference in delta KD emerged (IMI -0.005 +/- 0.010 pmol/ml versus FLU 0.008 +/- 0.013 at p = 004). Moreover, the changes in KD and HAMD17 trended to a positive correlation among only the FLU-treated subjects (4 = 0.406, p = .095). The clinical effects of 5-HT-based selective antidepressant may be reflected by dynamic changes in the platelet 5-HT uptake apparatus. These data suggest that the baseline confirmational status of the [3H]-IMI:5-HT transporter may reflect a "capacity" for a treatment response.

Adolescent↗

PubMed1996

Immunologic effects of insulin lispro [Lys (B28), Pro (B29) human insulin] in IDDM and NIDDM patients previously treated with insulin.

Insulin lispro [Lys (B28), Pro (B29) human insulin] is a rapidly absorbed analog that has diminished tendency to self-associate. In four open-label, 1-year-long international randomized trials, we contrasted the immunogenicity of insulin lispro versus regular human insulin (RHI) in patients previously treated with insulin who had IDDM or NIDDM. Using a self-blank subtraction assay, we assessed sera for the presence of insulin-specific antibodies (ISA), insulin lispro-specific antibodies (LSA), and cross-reactive antibodies (CRA). Basal insulin needs were provided either with human ultralente (UL) or NPH insulins. After 2 to 4 weeks of therapy with RHI plus UL or RHI plus NPH, 50% of patients were randomly assigned to begin insulin lispro or continue on RHI. At baseline, few pretreated patients had LSA (0-4%) and approximately 10% had ISA, whereas 41-45% of patients with IDDM and 23-27% of patients with NIDDM had CRA (IDDM vs. NIDDM, P < 0.001). Within studies, no significant differences were noted over time in ISA, LSA, or CRA attributable to the type of short-acting insulin. When data were pooled, inconsistent changes were noted in ISA and LSA (LSA were greater in NIDDM vs. IDDM at baseline, P = 0.001, and ISA were greater in IDDM vs. NIDDM at 6 months, P = 0.007). Significant levels of CRA were more common in IDDM at all times (P < 0.001, P = 0.022, and P = 0.002 at baseline, 6 months, and 12 months, respectively). For patients receiving insulin lispro, no significant changes occurred in antibody status among IDDM and NIDDM patients throughout the study (became positive, remained positive, became negative, or remained negative). IDDM patients were more likely to develop or maintain CRA levels (P = 0.008 vs. NIDDM), whereas antibody levels were comparable among positive individuals. No evidence was noted that insulin lispro differs in immunogenicity from RHI in previously treated IDDM and NIDDM patients.

Adult↗

PubMedDate not supplied

Internal pilot studies for estimating sample size.

We develop the idea of using data from the first 'few' patients entered in a clinical trial to estimate the final trial size needed to have specified power for rejecting H0 in favour of H1 if a real difference exists. When comparing means derived from Normally distributed data, there is no important effect on test size, power or expected trial size, provided that a minimum of about 20 degrees of freedom are used to estimate residual variance. Relative advantages and disadvantages of using larger internal pilot studies are presented. These revolve around crude expectations of the final study size, recruitment rate, duration of follow-up and practical constraints on the ability to prevent the circulation of unblinded randomization codes to investigators and those involved in editing and checking data.

Clinical Trials as Topic↗