OBJECTIVE -The purpose of this study was to examine possible factors associated with the increased risk of fractures observed with rosiglitazone in A Diabetes Outcome Progression Trial (ADOPT).RESEARCH DESIGN AND METHODS -Data from the 1,840 women and 2,511 men randomly assigned in ADOPT to rosiglitazone, metformin, or glyburide for a median of 4.0 years were examined with respect to time to first fracture, rates of occurrence, and sites of fractures.RESULTS -In men, fracture rates did not differ between treatment groups. In women, at least one fracture was reported with rosiglitazone in 60 patients (9.3% of patients, 2.74 per 100 patient-years), metformin in 30 patients (5.1%, 1.54 per 100 patient-years), and glyburide in 21 patients (3.5%, 1.29 per 100 patient-years). The cumulative incidence (95% CI) of fractures in women at 5 years was 15.1% (11.2-19.1) with rosiglitazone, 7.3% (4.4 -10.1) with metformin, and 7.7% (3.7-11.7) with glyburide, representing hazard ratios (95% CI) of 1.81 (1.17-2.80) and 2.13 (1.30 -3.51) for rosiglitazone compared with metformin and glyburide, respectively. The increase in fractures with rosiglitazone occurred in pre-and postmenopausal women, and fractures were seen predominantly in the lower and upper limbs. No particular risk factor underlying the increased fractures in female patients who received rosiglitazone therapy was identified.CONCLUSIONS -Further investigation into the risk factors and underlying pathophysiology for the increased fracture rate in women taking rosiglitazone is required to relate them to preclinical data and better understand the clinical implications of and possible interventions for these findings.

OBJECTIVEADOPT (A Diabetes Outcome Progression Trial) demonstrated that initial monotherapy with rosiglitazone provided superior durability of glycemic control compared with metformin and glyburide in patients with recently diagnosed type 2 diabetes. Herein, we examine measures of β-cell function and insulin sensitivity from an oral glucose tolerance test (OGTT) over a 4-year period among the three treatments.RESEARCH DESIGN AND METHODSRecently diagnosed, drug-naïve patients with type 2 diabetes (4,360 total) were treated for a median of 4.0 years with rosiglitazone, metformin, or glyburide and were examined with periodic metabolic testing using an OGTT.RESULTSMeasures of β-cell function and insulin sensitivity from an OGTT showed more favorable changes over time with rosiglitazone versus metformin or glyburide. Persistent improvements were seen in those who completed 4 years of monotherapy and marked deterioration of β-cell function in those who failed to maintain adequate glucose control with initial monotherapy.CONCLUSIONSThe favorable combined changes in β-cell function and insulin sensitivity over time with rosiglitazone appear to be responsible for its superior glycemic durability over metformin and glyburide as initial monotherapy in type 2 diabetes.

While bisphosphonates reduce fracture risk over 3 to 5 years, the optimal duration of treatment is uncertain. In a randomized extension study (E1) of the Health Outcomes and Reduced Incidence with Zoledronic Acid Once YearlyÀPivotal Fracture Trial (HORIZONÀPFT), zoledronic acid (ZOL) 5 mg annually for 6 years showed maintenance of bone mineral density (BMD), decrease in morphometric vertebral fractures, and a modest reduction in bone turnover markers (BTMs) compared with discontinuation after 3 years. To investigate the longer-term efficacy and safety of ZOL, a second extension (E2) was conducted to 9 years in which women on ZOL for 6 years in E1 were randomized to either ZOL (Z9) or placebo (Z6P3) for 3 additional years. In this multicenter, randomized, double-blind study, 190 women were randomized to Z9 (n ¼ 95) and Z6P3 (n ¼ 95). The primary endpoint was change in total hip BMD at year 9 vs. year 6 in Z9 compared with Z6P3. Other secondary endpoints included fractures, BTMs, and safety. From year 6 to 9, the mean change in total hip BMD was À0.54% in Z9 vs. À1.31% in Z6P3 (difference 0.78%; 95% confidence interval [CI]: À0.37%, 1.93%; p ¼ 0.183). BTMs showed small, non-significant increases in those who discontinued after 6 years compared with those who continued for 9 years. The number of fractures was low and did not significantly differ by treatment. While generally safe, there was a small increase in cardiac arrhythmias (combined serious and non-serious) in the Z9 group but no significant imbalance in other safety parameters. The results suggest almost all patients who have received six annual ZOL infusions can stop medication for up to 3 years with apparent maintenance of benefits.

Commonly measured bone biomarkers suggest that changes in bone resorption may be partly responsible for the increased risk of fracture in women taking thiazolidinediones.