Myocardial infarction and gastro-intestinal bleeding risks associated with aspirin use among elderly individuals with type 2 diabetes

Figures & data

Figure 1. Selection of study subjects.

Table I. Distribution of matching variables of cases and controls.

Characteristics	Outcome: MI		Outcome: GI bleeding
	Cases n = 1101 n (%)	Controls n = 5477 n (%)	Cases n = 373 n (%)	Controls n = 1853 n (%)
Sex
Female	543 (49)	2698 (49)	170 (46)	844 (46)
Male	558 (51)	2779 (51)	203 (54)	1009 (54)
Age (years)^a
66–70	383 (35)	1915 (35)	139 (37)	694 (37)
71–75	306 (28)	1530 (28)	93 (25)	465 (25)
76–80	246 (22)	1230 (22)	93 (25)	465 (25)
81–85	115 (10)	575 (10)	29 (8)	145 (8)
86–90	46 (4)	216 (4)	17 (5)	79 (4)
≥ 91	5 (0.5)	11 (0.2)	2 (0.5)	5 (0.3)
Year of cohort entry
1998	356 (32)	1780 (33)	103 (28)	512 (28)
1999	248 (23)	1228 (22)	94 (25)	467 (25)
2000	207 (19)	1033 (19)	70 (18)	346 (19)
2001	147 (13)	721 (13)	61 (16)	303 (16)
2002	89 (8)	445 (8)	31 (8)	155 (8)
2003	54 (5)	270 (5)	14 (4)	70 (4)

^aMatching was based on the individual's exact age. Grouping in Table I was performed for presentation purposes only.

Table II. Adjusted odds ratios (AOR) of myocardial infarction (MI).

	AOR^a	95% CI	P
Aspirin
Non-use	1.00	–
Current use	0.89	0.71–1.13	0.63
Past use	0.81	0.62–1.06	0.22
Duration of use (by 30-day periods of exposure)	0.99	0.98–1.01	0.19
Potentially confounding variables^a
Cardiovascular disease during the observation period
Ischemic heart disease	2.64	2.18–3.20	< 0.0001
Other forms of heart disease	1.50	1.24–1.81	< 0.0001
Hemorrhagic cerebrovascular disease	1.21	0.46–3.20	0.69
Ischemic cerebrovascular disease	1.36	1.06–1.74	0.02
Initial antidiabetes drug regimen
Sulfonylurea	1.00	–
Metformin	0.82	0.71–0.94	0.006
Thiazolidinedione	< 0.001	< 0.001–> 999.99	0.97
Other	0.71	0.40–1.26	0.24
Combination of at least 2 different drugs	0.82	0.58–1.15	0.19
Number of medications during follow-up
First tertile (1–8 drugs)	1.00	–
Second tertile (9–15 drugs)	1.32	1.09–1.59	0.002
Third tertile (≥ 16 drugs)	1.48	1.17–1.88	0.0005

^aAge, sex, and year of entry in the cohort entry were accounted for by study design (matching). Other variables included as covariates in the multivariate models were: region of residence, income, insulin use during follow-up, ACE inhibitors use, other antihypertensive drug use, statin use, other cholesterol-lowering drug use, number of physician encounters during follow-up, hospitalization during follow-up, obesity, and renal diseases. The association between those variables and MI was not statistically significant (results not shown).

Table III. Adjusted odds ratios (AOR) of gastro-intestinal (GI) bleeding.

	AOR^a	95% CI	P
Aspirin
Non-use	1.00	–
Current use	2.19	1.53–3.13	< 0.0001
Past use	1.47	0.91–2.38	0.12
Duration of use (by 30-day periods of exposure)	0.98	0.97–1.00	0.09
Potentially confounding variables ^a
Income
High (no premium subsidy)	1.00	–
Intermediate (partial premium subsidy)	0.83	0.64–1.08	0.17
Low (premium subsidy)	0.55	0.32–0.92	0.02
Number of medications during follow-up
First tertile (1–8 drugs)	1.00	–
Second tertile (9–14 drugs)	1.12	0.80–1.58	0.51
Third tertile (≥ 15 drugs)	1.10	0.69–1.74	0.69
Number of physician encounters during follow-up
First tertile (0–15 encounters)	1.00	–
Second tertile (16–48 encounters)	2.31	1.54–3.49	< 0.0001
Third tertile (≥ 49 encounters)	3.86	2.26–6.60	< 0.0001
Acetaminophen
Non-use	1.00	–
Current use	1.79	1.11–2.90	0.02
Past use	1.17	0.85–1.61	0.33
Duration of use (by 30-day periods of exposure)	1.00	0.97–1.03	0.98
Oral corticosteroids
Non-use	1.00	–
Current use	0.88	0.42–1.86	0.74
Past use	1.32	0.83–2.12	0.24
Duration of use (by 30-day periods of exposure)	1.02	0.98–1.07	0.36
Cytoprotective agents
Non-use	1.00	–
Current use	1.72	1.15–2.58	0.01
Past use	1.25	0.87–1.82	0.24
Duration of use (by 30-day periods of exposure)	0.98	0.96–1.00	0.03
Cox-1 NSAIDs
Non-use	1.00	–
Current use	2.10	1.11–3.94	0.02
Past use	0.71	0.48–1.07	0.10
Duration of use (by 30-day periods of exposure)	1.00	0.95–1.04	0.79
Cox-2 NSAIDs
Non-use	1.00	–
Current use	1.39	0.86–2.25	0.18
Past use	0.80	0.56–1.14	0.22
Duration of use (by 30-day periods of exposure)	0.98	0.95–1.01	0.10

^aAge, sex, and year of entry in the cohort were accounted for by the study design (matching). Other variables included as covariates in the multivariate models were: region of residence, initial antidiabetes used, insulin use during follow-up, and hospitalization during follow-up (results not shown).