Biomedical subjects

Dennis D Kim

Publications and source records attributed to Dennis D Kim.

12 recordsLinked to original sources

PubMed2007

Proximally placed alignment control strap for ankle varus deformity: a case report.

Ankle varus is a commonly encountered deformity in patients with neurologic or musculoskeletal disorders. It impedes stability during the stance phase of gait and often causes skin lesions on the lateral ankle area. Plastic or conventional ankle-foot orthoses (AFOs) with supplementary features such as a T-strap or increased contact area of the lateral flange have been used for correctable varus deformities. These supplementary modifications, however, have limitations as effective tools for varus control, and ankle varus may persist despite their use. We are revisiting the concept of a proximally placed alignment control strap for ankle varus, which may overcome the limitations of currently available modifications. This alignment control strap is designed to provide a medially directed force on the tibia and fibula against the force of varus deformation of the ankle. This modification can be easily added to various types of existing AFOs with acceptable aesthetic appearance. We describe 2 cases of manually correctable but persistent varus deformities of the ankle that were successfully controlled by utilization of the proximally placed alignment control strap.

Adult↗

PubMed2006

Immunogenicity of xenopeptide hormone therapies.

Peptides are a growing class of agents whose therapeutic use originated with non-human treatments such as animal insulins. Xenopeptides continue to be explored for biotherapeutic development using genetic engineering, and through the rich resource of animal and plant polypeptides. One of the major concerns of therapeutic administration of xenopeptides is the potential for untoward immune responses that may lead to loss of drug efficacy or adverse events in recipients. An increased risk of immunogenicity is perceived with xenopeptides, however, human-derived therapies also induce antibody formation that in some cases has been associated with severe clinical sequelae. In this review, antibody responses to xenopeptides are highlighted looking at current hormone therapies used to treat endocrine disorders. Similar to clinical experiences with peptide-based agents in general, antibody responses against xenopeptide hormone therapies in majority of cases have been benign in nature with minimal clinical impact.

Animals↗

PubMed2005

Exenatide augments first- and second-phase insulin secretion in response to intravenous glucose in subjects with type 2 diabetes.

CONTEXT: First-phase insulin secretion (within 10 min after a sudden rise in plasma glucose) is reduced in type 2 diabetes mellitus (DM2). The incretin mimetic exenatide has glucoregulatory activities in DM2, including glucose-dependent enhancement of insulin secretion. OBJECTIVE: The objective of the study was to determine whether exenatide can restore a more normal pattern of insulin secretion in subjects with DM2. DESIGN: Fasted subjects received iv insulin infusion to reach plasma glucose 4.4-5.6 mmol/liter. Subjects received iv exenatide (DM2) or saline (DM2 and healthy volunteers), followed by iv glucose challenge. PATIENTS: Thirteen evaluable DM2 subjects were included in the study: 11 males, two females; age, 56 +/- 7 yr; body mass index, 31.7 +/- 2.4 kg/m2; hemoglobin A1c, 6.6 +/- 0.7% (mean +/- sd) treated with diet/exercise (n = 1), metformin (n = 10), or acarbose (n = 2). Controls included 12 healthy, weight-matched subjects with normal glucose tolerance: nine males, three females; age, 57 +/- 9 yr; and body mass index, 32.0 +/- 3.0 kg/m2. SETTING: The study was conducted at an academic hospital. MAIN OUTCOME MEASURES: Plasma insulin, plasma C-peptide, insulin secretion rate (derived by deconvolution), and plasma glucagon were the main outcome measures. RESULTS: DM2 subjects administered saline had diminished first-phase insulin secretion, compared with healthy control subjects. Exenatide-treated DM2 subjects had an insulin secretory pattern similar to healthy subjects in both first (0-10 min) and second (10-180 min) phases after glucose challenge, in contrast to saline-treated DM2 subjects. In exenatide-treated DM2 subjects, the most common adverse event was moderate nausea (two of 13 subjects). CONCLUSIONS: Short-term exposure to exenatide can restore the insulin secretory pattern in response to acute rises in glucose concentrations in DM2 patients who, in the absence of exenatide, do not display a first phase of insulin secretion. Loss of first-phase insulin secretion in DM2 patients may be restored by treatment with exenatide.

Adult↗

PubMed2005

Pharmacokinetics, pharmacodynamics, and safety of exenatide in patients with type 2 diabetes mellitus.

PURPOSE: The pharmacology and tolerability of exenatide in patients with type 2 diabetes mellitus were studied. METHODS: Two randomized, single-blind, placebo-controlled studies were conducted. Treatment with oral antidiabetic agents was stopped 14 days before study initiation. In the first study (study A), eight subjects received placebo, 0.1-, 0.2-, 0.3-, and either 0.4-microg/kg exenatide or placebo five minutes before a meal combined with liquid acetaminophen (to assess the rate of gastric emptying) on days 1, 3, 5, 7, and 9. In the second study (study B), subjects received a single s.c. dose of exenatide or placebo on consecutive days. Part 1 of study B used exenatide doses of 0.01 and 0.1 microg/ kg; 0.02-, 0.05-, and 0.1-microg/kg doses were given in part 2. After an overnight fast, the study drug was injected 15 minutes before a meal (part 1) and before a meal and acetaminophen (part 2). Parts 1 and 2 of study B enrolled six and eight patients, respectively. RESULTS: In both studies, plasma exenatide pharmacokinetic profiles appeared dose proportional. Exenatide doses of 0.02-0.2 microg/kg dose-dependently lowered postprandial glucose excursions. Exenatide suppressed postprandial plasma glucagon and slowed gastric emptying. There were no serious adverse events and no patient withdrawals related to treatment. Nausea and vomiting were the most common adverse events and were mild to moderate in severity at doses ranging from 0.02 to 0.2 microg/kg. CONCLUSION: Administration of preprandial exenatide by s.c. injection resulted in dose-proportional exenatide pharmacokinetics and antidiabetic pharmacodynamic activity. At doses ranging from 0.02 to 0.2 microg/kg, exenatide dose-dependently reduced postprandial plasma glucose excursion by insulinotropism, suppression of plasma glucagon, and slowing of gastric emptying.

Administration, Oral↗

PubMed2005

Effects of exenatide (exendin-4) on glycemic control over 30 weeks in patients with type 2 diabetes treated with metformin and a sulfonylurea.

OBJECTIVE: This study evaluated the effects of exenatide, a novel incretin mimetic, in hyperglycemic patients with type 2 diabetes unable to achieve glycemic control with metformin-sulfonylurea combination therapy. RESEARCH DESIGN AND METHODS: A 30-week, double-blind, placebo-controlled study was performed in 733 subjects (aged 55 +/- 10 years, BMI 33.6 +/- 5.7 kg/m(2), A1C 8.5 +/- 1.0%; means +/- SD) randomized to 5 microg subcutaneous exenatide b.i.d. (arms A and B) or placebo for 4 weeks. Thereafter, arm A remained at 5 microg b.i.d. and arm B escalated to 10 microg b.i.d. Subjects continued taking their dose of metformin and were randomized to either maximally effective (MAX) or minimum recommended (MIN) doses of sulfonylurea. RESULTS: Week 30 A1C changes from baseline (+/-SE) were -0.8 +/- 0.1% (10 microg), -0.6 +/- 0.1% (5 microg), and +0.2 +/- 0.1% (placebo; adjusted P < 0.0001 vs. placebo), yielding placebo-adjusted reductions of -1.0% (10 microg) and -0.8% (5 microg). In the evaluable population, exenatide-treated subjects were more likely to achieve A1C < or =7% than placebo-treated subjects (34% [10 microg], 27% [5 microg], and 9% [placebo]; P < 0.0001). Both exenatide arms demonstrated significant weight loss (-1.6 +/- 0.2 kg from baseline each exenatide arm, -0.9 +/- 0.2 kg placebo; P < or = 0.01 vs. placebo). Mild or moderate nausea was the most frequent adverse event. The incidence of mild/moderate hypoglycemia was 28% (10 microg), 19% (5 microg), and 13% (placebo) and appeared lower with MIN than with MAX sulfonylurea treatment. CONCLUSIONS: Exenatide significantly reduced A1C in patients with type 2 diabetes unable to achieve adequate glycemic control with maximally effective doses of combined metformin-sulfonylurea therapy. This improvement in glycemic control was associated with no weight gain and was generally well tolerated.

Adult↗

PubMed2005

Effects of exenatide (exendin-4) on glycemic control and weight over 30 weeks in metformin-treated patients with type 2 diabetes.

OBJECTIVE: This study evaluates the ability of the incretin mimetic exenatide (exendin-4) to improve glycemic control in patients with type 2 diabetes failing to achieve glycemic control with maximally effective metformin doses. RESEARCH DESIGN AND METHODS: A triple-blind, placebo-controlled, 30-week study at 82 U.S. sites was performed with 336 randomized patients. In all, 272 patients completed the study. The intent-to-treat population baseline was 53 +/- 10 years with BMI of 34.2 +/- 5.9 kg/m(2) and HbA(1c) of 8.2 +/- 1.1%. After 4 weeks of placebo, subjects self-administered 5 microg exenatide or placebo subcutaneously twice daily for 4 weeks followed by 5 or 10 microg exenatide, or placebo subcutaneously twice daily for 26 weeks. All subjects continued metformin therapy. RESULTS: At week 30, HbA(1c) changes from baseline +/- SE for each group were -0.78 +/- 0.10% (10 microg), -0.40 +/- 0.11% (5 microg), and +0.08 +/- 0.10% (placebo; intent to treat; adjusted P < 0.002). Of evaluable subjects, 46% (10 microg), 32% (5 microg), and 13% (placebo) achieved HbA(1c) < or =7% (P < 0.01 vs. placebo). Exenatide-treated subjects displayed progressive dose-dependent weight loss (-2.8 +/- 0.5 kg [10 microg], -1.6 +/- 0.4 kg [5 microg]; P < 0.001 vs. placebo). The most frequent adverse events were gastrointestinal in nature and generally mild to moderate. Incidence of mild to moderate hypoglycemia was low and similar across treatment arms, with no severe hypoglycemia. CONCLUSIONS: Exenatide was generally well tolerated and reduced HbA(1c) with no weight gain and no increased incidence of hypoglycemia in patients with type 2 diabetes failing to achieve glycemic control with metformin.

Adult↗

PubMed2004

Effects of exenatide (exendin-4) on glycemic control over 30 weeks in sulfonylurea-treated patients with type 2 diabetes.

OBJECTIVE: This study evaluated the ability of the incretin mimetic exenatide (exendin-4) to improve glycemic control in patients with type 2 diabetes failing maximally effective doses of a sulfonylurea as monotherapy. RESEARCH DESIGN AND METHODS: This was a triple-blind, placebo-controlled, 30-week study conducted at 101 sites in the U.S. After a 4-week, single-blind, placebo lead-in period, 377 subjects were randomized (60% men, age 55 +/- 11 years, BMI 33 +/- 6 kg/m(2), HbA(1c) 8.6 +/- 1.2% [+/-SD]) and began 4 weeks at 5 microg subcutaneous exenatide twice daily (before breakfast and dinner; arms A and B) or placebo. Subsequently, subjects in arm B were escalated to 10 microg b.i.d. exenatide. All subjects continued sulfonylurea therapy. RESULTS: At week 30, HbA(1c) changes from baseline were -0.86 +/- 0.11, -0.46 +/- 0.12, and 0.12 +/- 0.09% (+/-SE) in the 10-microg, 5-microg, and placebo arms, respectively (adjusted P < 0.001). Of evaluable subjects with baseline HbA(1c) > 7% (n = 237), 41% (10 microg), 33% (5 microg), and 9% (placebo) achieved HbA(1c) <or= 7% (P < 0.001). Fasting plasma glucose concentrations decreased in the 10-microg arm compared with placebo (P < 0.05). Subjects in the exenatide arms had dose-dependent progressive weight loss, with an end-of-study loss in the 10-microg exenatide arm of -1.6 +/- 0.3 kg from baseline (P < 0.05 vs. placebo). The most frequent adverse events were generally mild or moderate and gastrointestinal in nature. No severe hypoglycemia was observed. CONCLUSIONS: Exenatide significantly reduced HbA(1c) in patients with type 2 diabetes failing maximally effective doses of a sulfonylurea. Exenatide was generally well tolerated and was associated with weight loss.

Adult↗

PubMed2003

Pramlintide reduces postprandial glucose excursions when added to regular insulin or insulin lispro in subjects with type 1 diabetes: a dose-timing study.

OBJECTIVE: To assess the postprandial glucose-lowering effect of the human amylin analog pramlintide when given with either regular insulin or insulin lispro in subjects with type 1 diabetes, with an emphasis on the optimal dose timing relative to meals. RESEARCH DESIGN AND METHODS: In this randomized, single-blind, placebo-controlled, five-way crossover study, 19 subjects with type 1 diabetes using regular insulin and 21 subjects with type 1 diabetes using insulin lispro underwent five consecutive mixed meal tests. In randomized order, subjects received subcutaneous injections of placebo at -15 min or 60 microg pramlintide at -15, 0, +15, or +30 min relative to the meal after an overnight fast. Regular insulin or insulin lispro was injected at -30 and 0 min, respectively, at doses that were adjusted appropriately for both the content of the standardized meal and the anticipated effects of pramlintide. Plasma glucose concentrations were measured before and during the 4-h postmeal period. RESULTS: In both the regular insulin and insulin lispro groups, pramlintide injections at all four time points lowered the postprandial glucose excursion (36 to >100% reduction in incremental area under the concentration time curve from 0 to 4 h (AUC(0-4 h)) compared with placebo. However, only preprandial injections of pramlintide (-15 and 0 min) were able to prevent the initial postprandial surge in glucose. The optimal time for pramlintide injection was 0 min, which reduced the postprandial glucose excursion by >100% compared with regular insulin plus placebo (incremental AUC(0-4 h): -0.6 +/- 2.5 vs. 11.0 +/- 2.9 mmolx h(-1) x l(-1), P < 0.0007) and by 75% compared with insulin lispro plus placebo (incremental AUC(0-4 h): 2.5 +/- 2.1 vs. 10.0 +/- 2.5 mmol x h(-1) x l(-1), P < 0.0098). No serious adverse events were reported. CONCLUSIONS: Pramlintide, given at or just before a meal, reduces the postprandial glucose excursion in subjects with type 1 diabetes, regardless of whether added to regular insulin or a rapid-acting insulin analog.

Adolescent↗

PubMed2002

Regulation of glucose transport and insulin signaling by troglitazone or metformin in adipose tissue of type 2 diabetic subjects.

Type 2 diabetic subjects failing glyburide therapy were randomized to receive additional therapy with either metformin (2,550 mg/day) or troglitazone (600 mg/day) for 3-4 months. Biopsies of subcutaneous abdominal adipose tissue were obtained before and after therapy. Glycemic control was similar with both treatments. Metformin treatment increased insulin-stimulated whole-body glucose disposal rates by 20% (P < 0.05); the response to troglitazone was greater (44% increase, P < 0.01 vs. baseline, P < 0.05 vs. metformin). Troglitazone-treated subjects displayed a tendency toward weight gain (5 +/- 2 kg, P < 0.05), increased adipocyte size, and increased serum leptin levels. Metformin-treated subjects were weight-stable, with unchanged leptin levels and reduced adipocyte size (to 84 +/- 4% of control, P < 0.005). Glucose transport in isolated adipocytes from metformin-treated subjects was unaltered from pretreatment. Glucose transport in both the absence (321 +/- 134% of pre-Rx, P < 0.05) and presence of insulin (418 +/- 161%, P < 0.05) was elevated after troglitazone treatment. Metformin treatment had no effect on adipocyte content of GLUT1 or GLUT4 proteins. After troglitazone treatment, GLUT4 protein expression was increased twofold (202 +/- 42%, P < 0.05). Insulin-stimulated serine phosphorylation of Akt was augmented after troglitazone (170 +/- 34% of pre-Rx response, P < 0.05) treatment and unchanged by metformin. We conclude that the ability of troglitazone to upregulate adipocyte glucose transport, GLUT4 expression, and insulin signaling can contribute to its greater effect on whole-body glucose disposal.

Adipocytes↗

PubMed2002

Differential effects of metformin and troglitazone on cardiovascular risk factors in patients with type 2 diabetes.

OBJECTIVE: Traditional cardiovascular risk factors (CVRF) only partly explain the excessive risk of cardiovascular disease in patients with type 2 diabetes. There is now an increasing appreciation for many novel CVRF that occur largely as a result of insulin resistance and hyperinsulinemia. Therefore, we investigated whether diabetes medications that vary in their mechanism of action and ability to reduce insulin resistance may differ in their effects on both traditional and novel CVRF. RESEARCH DESIGN AND METHODS: We compared the addition of metformin or troglitazone therapy on CVRF in 22 subjects with type 2 diabetes who remained in poor glycemic control (with HbA1c >8.5%) while taking glyburide 10 mg twice daily. Subjects were initially randomized to either metformin 850 mg once daily or troglitazone 200 mg once daily. Both medications were then titrated upward as needed to achieve fasting plasma glucose <120 mg/dl. Measures of glucose control, insulin resistance, and CVRF (blood pressure, lipids, plasminogen activator inhibitor-1, C-reactive protein, fibrinogen, and small dense LDL) were assessed both before and after therapy. RESULTS: After 4 months of treatment, both metformin and troglitazone led to similar decreases in fasting plasma glucose and HbA1c. The reduction in insulin resistance determined by hyperinsulinemic-euglycemic clamp was nearly twofold greater with troglitazone than metformin. Metformin did not induce significant changes in blood pressure, LDL cholesterol, LDL size, HDL cholesterol, triglycerides, or plasminogen activator inhibitor-1. However, C-reactive protein did decrease by 33% (6 +/- 1 to 4 +/- 1 mg/l; P < 0.01) [corrected]. Troglitazone therapy was associated with increases in LDL size (26.21 +/- 0.22 to 26.56 +/- 0.25 nm; P=0.04) and HDL cholesterol (33 +/- 3 to 36 +/- 3 mg/dl; P=0.05) and decreases in triglycerides (197 +/- 19 to 155 +/- 23 mg/dl; P=0.07) and C-reactive protein by 60% (8 +/- 3 to 3 +/- 1 mg/l, P < 0.01) [corrected]. CONCLUSIONS: For patients with type 2 diabetes in whom maximal sulfonylurea therapy failed, the addition of the insulin sensitizer troglitazone seemed to have greater benefits on several traditional and novel CVRF than metformin therapy. These differences were not related to glycemic improvement but reflected, in part, the greater reduction in insulin resistance obtained with addition of troglitazone. These data suggest that medications that more effectively address this underlying metabolic defect may be more beneficial in reducing cardiovascular risk in type 2 diabetes.

Blood Glucose↗

PubMedDate not supplied

Effectiveness of progressive dose-escalation of exenatide (exendin-4) in reducing dose-limiting side effects in subjects with type 2 diabetes.

BACKGROUND: Exenatide (exendin-4) exhibits dose-dependent glucoregulatory activity, but causes dose-limiting nausea and vomiting. This study was designed to formally assess the possibility of inducing tolerance to the side effects of nausea and vomiting at therapeutic doses of exenatide, using a dose-escalation methodology. METHODS: In this two-arm, triple-blind, multicenter study, 123 subjects with type 2 diabetes were enrolled and randomized; 99 (80.5%) of them completed the study. Subjects in the exenatide-primed arm received subcutaneous exenatide, starting at 0.02 micro g/kg three times a day (TID) and increasing in 0.02 micro g/kg per dose increments every 3 days for 35 days. Subjects in the exenatide-naive arm received placebo TID for 35 days. At the end of this 35-day regimen, subjects in both arms received the same highest dose of exenatide (0.24 micro g/kg TID) for 3 days. Thus, the exenatide-naive arm received exenatide for the first time on Day 35. RESULTS: The exenatide-primed arm had a lower proportion of subjects experiencing nausea and vomiting in response to exposure to the highest dose of exenatide (27 vs 56% in the exenatide-naive arm; p = 0.0018). Kaplan-Meier estimates of cumulative incidence were 0.28 in the exenatide-primed arm, compared with 0.68 in the exenatide-naive arm (p </= 0.001). As predicted by the study design, fewer subjects in the exenatide-primed arm reported severe nausea (29%) and vomiting (10%) than those in the exenatide-naive arm (48 and 31%, respectively). In the exenatide-primed arm, fasting serum glucose progressively declined over the first 35 days of dosing, but was unchanged in the exenatide-naive arm (placebo phase) during the same interval. CONCLUSION: Gradual dose-escalation of exenatide successfully reduced the proportion of subjects experiencing dose-limiting nausea and vomiting, with no loss of glucoregulatory activity, thus demonstrating the value of gradual dose-escalation in mitigating the gastrointestinal side effects of exenatide.

Adolescent↗

PubMedDate not supplied

Exenatide elicits sustained glycaemic control and progressive reduction of body weight in patients with type 2 diabetes inadequately controlled by sulphonylureas with or without metformin.

BACKGROUND: In two placebo-controlled 30-week trials, treatment with exenatide reduced HbA(1c) and body weight in patients with type 2 diabetes in the context of sulphonylurea (SU) or SU plus metformin (MET) as background treatment. This analysis examines the effects of 82 weeks of exenatide treatment for participants in these earlier 30-week trials. METHODS: Data were pooled from the two pivotal trials of exenatide added to SU or SU plus MET. Both 30-week, placebo-controlled trials of 5 microg or 10 microg exenatide b.i.d. were followed by 52-week open-label, uncontrolled extension studies in which all participants received 10 microg exenatide b.i.d. and continued prior oral therapies. This interim analysis includes data for 222 patients who completed 82 weeks of exenatide treatment (61% M, age 57 +/- 10 y, weight 99 +/- 21 kg, BMI 34 +/- 6 kg/m(2), HbA(1c)8.4 +/- 1.0% [mean +/- SD]). RESULTS: Reduction in HbA(1c) from baseline to week 30 (-0.8 +/- 0.1% and -1.0 +/- 0.1% for 5 microg b.i.d. and 10 microg b.i.d., respectively [mean +/- SE]) was sustained up to week 82 (-1.0 +/- 0.1%). Of 207 patients with baseline HbA(1c) > 7%, 44% achieved HbA(1c) < or = 7% at week 82. Reduction of body weight from baseline to week 30 (-1.4 +/- 0.3 kg and -2.1 +/- 0.3 kg for 5 microg b.i.d. and 10 microg b.i.d., respectively) was progressive up to week 82 (-4.0 +/- 0.3 kg). The most frequent adverse events were nausea and hypoglycaemia, both generally mild to moderate in intensity. CONCLUSIONS: Exenatide added to maximally effective doses of SU or SU plus MET resulted in a sustained reduction in HbA(1c) and a progressive reduction in weight over 1 1/2 years.

Adolescent↗