Type 2 Diabetes
Conditions
Keywords
type 2 diabetes, insulin, insulin injection, metformin, C-reactive protein, insulin sensitivity, glycemic control, inflammation
Brief summary
The purpose of this study, which is being conducted at 100 centers throughout the United States, is to determine whether Lantus, a long-acting insulin injection, either alone or in combination with metformin, is effective in reducing C-reactive protein (CRP) in adults with type 2 diabetes. CRP is a marker of chronic low-level inflammation, a new risk factor for diabetes, heart attack, stroke, and other cardiovascular events.
Detailed description
Study Rationale Low-grade systemic inflammation as indicated by elevated levels of C-reactive protein (CRP) is often present in patients with type 2 diabetes. Individuals with type 2 diabetes represent a vulnerable population in which cardiovascular event rates are high and among whom CRP reduction may have the greatest impact. While several classes of oral hypoglycemic agents have been shown to lower CRP, data are not available for newer formulations of long-acting insulins such as Lantus (insulin glargine injection) and no study has comprehensively evaluated the relative merit of insulin-providing versus insulin-sensitizing strategies for this purpose. Investigational Plan This is a multicenter, community-based, randomized 2x2 factorial trial of Lantus and metformin among patients with type 2 diabetes treated with either diet or oral monotherapy (other than metformin) only who have poor glycemic control and elevated CRP. The primary endpoint is change in CRP. Secondary endpoints include improvement in insulin sensitivity, glycemic control, blood lipids, as well as selected inflammatory and prothrombotic markers, and adipokine levels. Limited data suggest that short-term insulin administration in patients with poorly controlled type 2 diabetes may lower CRP, but the benefit of CRP reduction that is unique to insulin therapy and independent of glycemic control per se remains uncertain. The insulin-sensitizing agent metformin, a mainstay of anti-diabetic therapy, has been shown to reduce macrovascular complications among patients with type 2 diabetes and, in some but not all randomized clinical trials, also has a modest CRP-lowering effect. This study is designed to assess whether the use of Lantus either alone or in combination with metformin lowers CRP over a 14-week treatment period. Eligible men and women age 18 to 79 years with early diabetes on diet only or oral monotherapy with baseline HbA1c 7.0-10% and CRP greater than or equal to 2.0 mg/l will be randomized in a 2X2 factorial fashion as follows. First, participants will be assigned at random to open-label Lantus or no insulin. Then, within these two categories, subjects will be assigned at random to metformin or placebo. Thus, the four resultant treatment groups are Lantus injection and placebo pill, Lantus injection and metformin pill, metformin pill alone, and placebo pill alone. All patients will receive diet and exercise counseling. This study design will permit testing of the overall effect of Lantus as well as the effect of combination therapy with metformin for CRP reduction at a targeted level of glycemic control (fingerstick fasting blood glucose \< 110 mg/dl). All participants will be provided with a glucometer for fingerstick glucose testing calibrated to report plasma-referenced values.
Interventions
Once daily for 14 weeks
Up to 4 pils per day (2g per day) maximum
Up to 4 pills per day
Sponsors
Study design
Eligibility
Inclusion criteria
* Men and women aged 18 to 79 * Type 2 diabetes, treated only by diet or oral drugs other than metformin * HbA1c greater than or equal to 7% and less than or equal to 10% * C-reactive protein greater than or equal to 2 mg/L
Exclusion criteria
* Baseline use of metformin or insulin * Type 1 diabetes, history of ketoacidosis or positive anti-GAD antibody * History of congestive heart failure requiring drug therapy * Active liver disease * Kidney impairment * Recent initiation or change in dose of statins, fibric acid derivatives, angiotensin receptor blockers, nonsteroidal anti-inflammatory agents, or corticosteroids
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Percentage Reduction in C-reactive Protein (CRP) | 14 weeks |
Countries
United States
Participant flow
Recruitment details
Recruitment occurred at 73 US office-based practices between October 2006 and December 2008.
Pre-assignment details
Preenrollment evaluation comprised local laboratory testing of hsCRP,HbA1c, and safety parameters (ALT or AST and creatinine). Eligible participants were enrolled in a 2-week run-in. Ability to self-monitor fingerstick blood glucose and perform insulin injection was determined and evaluation for evidence of marked hyperglycemia was undertaken.
Participants by arm
| Arm | Count |
|---|---|
| Placebo Pill Placebo pill | 124 |
| Metformin Pill Metformin pill | 126 |
| Insulin Glargine Plus Placebo Pill Insulin glargine plus placebo pill | 126 |
| Insulin Glargine Plus Metformin Pill Insulin Glargine plus metformin pill | 124 |
| Total | 500 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 |
|---|---|---|---|---|---|
| Overall Study | Lost to Follow-up | 4 | 4 | 3 | 7 |
| Overall Study | Withdrawal by Subject | 4 | 2 | 1 | 1 |
Baseline characteristics
| Characteristic | Placebo Pill | Total | Insulin Glargine Plus Metformin Pill | Insulin Glargine Plus Placebo Pill | Metformin Pill |
|---|---|---|---|---|---|
| Age Continuous Mean (SD) | 54.0 years STANDARD_DEVIATION 10.9 | 53.9 years STANDARD_DEVIATION 11.4 | 54.0 years STANDARD_DEVIATION 11.7 | 53.8 years STANDARD_DEVIATION 11.4 | 53.8 years STANDARD_DEVIATION 11.5 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 13 Participants | 53 Participants | 17 Participants | 19 Participants | 4 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 110 Participants | 438 Participants | 105 Participants | 104 Participants | 119 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 1 Participants | 9 Participants | 2 Participants | 3 Participants | 3 Participants |
| Race/Ethnicity, Customized African American | 25 Participants | 108 Participants | 24 Participants | 25 Participants | 34 Participants |
| Race/Ethnicity, Customized Other | 8 Participants | 27 Participants | 9 Participants | 6 Participants | 4 Participants |
| Race/Ethnicity, Customized White | 91 Participants | 365 Participants | 91 Participants | 95 Participants | 88 Participants |
| Sex: Female, Male Female | 64 Participants | 281 Participants | 66 Participants | 83 Participants | 68 Participants |
| Sex: Female, Male Male | 60 Participants | 219 Participants | 58 Participants | 43 Participants | 58 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — | — / — |
| other Total, other adverse events | 12 / 124 | 18 / 126 | 21 / 126 | 17 / 124 |
| serious Total, serious adverse events | 3 / 124 | 8 / 126 | 2 / 126 | 0 / 124 |
Outcome results
Percentage Reduction in C-reactive Protein (CRP)
Time frame: 14 weeks
Population: As hsCRP was measured at both 6 and 14 weeks, linear mixed models conditioning on baseline hsCRP and adjusting for treatment stratum were constructed with the dependent variable being change in lnCRP. Any subject having either or both 6 week and 14 week measures was included.
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Placebo Pill | Percentage Reduction in C-reactive Protein (CRP) | -19.0 Percent CRP Reduction |
| Metformin Pill | Percentage Reduction in C-reactive Protein (CRP) | -16.1 Percent CRP Reduction |
| Insulin Glargine Plus Placebo Pill | Percentage Reduction in C-reactive Protein (CRP) | -2.9 Percent CRP Reduction |
| Insulin Glargine Plus Metformin Pill | Percentage Reduction in C-reactive Protein (CRP) | -20.1 Percent CRP Reduction |