Table 1

Demographics of the study cohort according to ever use of pioglitazone: the KPNC diabetes registry, 1997–2008

Ever use of pioglitazone*Never use of pioglitazone*
N30,173162,926
Age (years)
 40–498,612 (28.5)36,452 (22.4)
 50–599,945 (33.0)41,962 (25.8)
 60–697,799 (25.8)42,691 (26.2)
 ≥703,817 (12.7)41,821 (25.7)
Sex (female)14,157 (46.9)75,686 (46.5)
Race/ethnicity
 White14,768 (48.9)80,777 (49.6)
 Black2,823 (9.4)16,731 (10.3)
 Asian3,834 (12.7)18,877 (11.6)
 Hispanic3,320 (11.0)14,430 (8.9)
 Other1,691 (5.6)8,876 (5.4)
 Missing3,737 (12.4)23,235 (14.3)
Current smoker6,052 (20.1)28,023 (17.2)
Renal function
 Normal creatinine23,174 (76.8)125,879 (77.3)
 Elevated creatinine1248 (4.1)13,993 (8.6)
 Missing5,751 (19.1)23,054 (14.2)
Bladder condition3,686 (12.2)25,581 (15.7)
Congestive heart failure969 (3.2)11,038 (6.8)
Income
 Low§14,413 (47.8)82,270 (50.5)
 High12,825 (42.5)66,133 (40.6)
 Missing2,935 (9.7)14,523 (8.9)
Baseline A1C (%)
 <74,873 (16.2)46,407 (28.5)
 7–7.95,455 (18.1)31,517 (19.3)
 8–8.93,921 (13.0)17,060 (10.5)
 9–9.92,979 (9.9)11,524 (7.1)
 ≥107,330 (24.3)28,017 (17.2)
 Missing5,615 (18.6)28,401 (17.4)
Newly diagnosed with diabetes at the start of follow-up14,687 (48.7)94,739 (58.1)
Duration of diabetes (years)
 0–517,363 (57.5)102,916 (63.2)
 5–92,983 (9.9)9,671 (5.9)
 ≥102,956 (9.8)17,432 (10.7)
 Missing6,871 (22.8)32,907 (20.2)
Other cancer prior to baseline1,186 (3.9)8,762 (5.4)
Other diabetes medications
 Other TZDs2,754 (9.1)2,470 (1.5)
 Metformin24,797 (82.2)70,956 (43.6)
 Sulfonylureas26,311 (87.2)95,429 (58.6)
 Other oral hypoglycemic drugs1,482 (4.9)1,865 (1.1)
 Insulin13,123 (43.5)41,337 (25.4)
Pioglitazone use during follow-up
 Time since starting pioglitazone (months)39.5 (1–102)N/A
  <187,245 (24.0)N/A
  18–366,681 (22.1)N/A
  >3616,247 (53.8)N/A
 Duration of therapy (months)24.1 (1–102)N/A
  <127,332 (24.3)N/A
  12–247,677 (25.4)N/A
  >2415,164 (50.3)N/A
 Cumulative dose (mg)17,670 (450–179,000)N/A
  1–10,50010,281 (34.1)N/A
  10,501–28,0009,667 (32.0)N/A
  >28,00010,225 (33.9)N/A
  • Data are n (%) or median (range) unless otherwise indicated. N/A, not applicable.

  • *All comparisons have P values <0.01 except female sex (P = 0.46).

  • †Creatinine ≥1.4 mg/dL for women and ≥1.5 mg/dL for men.

  • ‡History of urinary tract infections, urolithiasis, incontinence, and other bladder or urethral conditions.

  • §Low income defined as median household income in census block below the cohort average ($59,000).

  • ¶Includes newly diagnosed patients and patients who newly enrolled in KPNC with an existing diagnosis of diabetes.