Hyperlipidemia patients with long-term statin treatment are associated with a reduced risk of progression of benign prostatic enlargement

Figures & data

Table 1. The International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes, the Taiwan National Health Insurance reimbursement procedure codes, and the anatomical therapeutic chemical (ATC) classification system codes used in the study.

Diagnosis/Procedure/Medication	Codes
Diagnosis	ICD-9-CM
Hyperlipidemia	272.x
Benign prostate hyperplasia	600.xx
Diabetes mellitus	250, 648.0
Chronic hypertension	401–405
Coronary heart disease	410.xx-414.xx
Obesity	278, 278.0, 278.00, 278.01
Liver cirrhosis	571.2, 571.5, and 571.6
Procedure	Procedure
Transurethral resection of the prostate	79406B (resection prostate chips of >5 g), 79411B (15–50 g), 79412B (>50 g)
Medication	ATC
Statins	C10AA
Nonsteroidal anti-inflammatory drugs	M01A
Metformin	A10BA02
Aspirin	B01AC06, B01AC30, N02BA01, and N02BA51
Lipid-lowering drugs except statins	C10AB, C10AC, C10AD, C10AX, C10BA, and C10BX
Alpha-blockers	G04CA
5-alpha reductase inhibitors	G04CB01, G04CB02

Figure 1. Flowchart of the study design. LHID: Longitudinal Health Insurance Database; BPE: benign prostate enlargement.

Table 2. Distribution of sample characteristics according to the duration of statin use in patients with hyperlipidemia.

	Statin use
	>365 days	181–365 days	91–180 days	31–90 days	None
	(n = 1604)	(n = 813)	(n = 739)	(n = 713)	(n = 4092)	p^a
Age, n (%)						<.001
40–49	693 (43.2)	375 (46.1)	348 (47.1)	341 (47.8)	2038 (49.8)
50–59	560 (34.9)	273 (33.6)	255 (34.5)	250 (35.1)	1315 (32.1)
60–69	266 (16.6)	115 (14.1)	99 (13.4)	81 (11.4)	497 (12.1)
70–99	85 (5.3)	50 (6.2)	37 (5)	41 (5.8)	242 (5.9)
Diabetes mellitus, n (%)	291 (18.1)	104 (12.8)	98 (13.3)	62 (8.7)	406 (9.9)	<.001
Hypertension, n (%)	556 (34.7)	242 (29.8)	208 (28.1)	159 (22.3)	901 (22)	<.001
Coronary heart disease, n (%)	144 (9)	62 (7.6)	52 (7)	52 (7.3)	239 (5.8)	.001
Obesity, n (%)	5 (0.3)	6 (0.7)	5 (0.7)	2 (0.3)	33 (0.8)	.193
Liver cirrhosis, n (%)	4 (0.2)	2 (0.2)	5 (0.7)	3 (0.4)	20 (0.5)	.514
NSAID use, n (%)	1173 (73.1)	611 (75.2)	547 (74)	523 (73.4)	2902 (70.9)	.055
Metformin use, n (%)	108 (6.7)	27 (3.3)	35 (4.7)	20 (2.8)	91 (2.2)	<.001
Aspirin use, n (%)	273 (17)	112 (13.8)	109 (14.7)	94 (13.2)	470 (11.5)	<.001
Lipid-lowering drugs except stains, n (%)	299 (18.6)	128 (15.7)	126 (17.1)	133 (18.7)	899 (22)	<.001
Urologist visits (mean ± SD)	3.06 ± 8.39	2.62 ± 9.09	2.34 ± 6.27	2.02 ± 6.16	2.86 ± 8.41	<.001

^a Evaluated by the chi-squared test or the Kruskal–Wallis H-test.

NSAID: nonsteroidal anti-inflammatory drug; SD: standard deviation.

Figure 2. The risk of having benign prostate hyperplasia progression in the cohort with statin use >365 days compared to the cohort that used no statins stratified by confounders. DM: diabetes mellitus; CHD: coronary heart disease; NSAIDs: nonsteroidal anti-inflammatory drugs; HR: hazard ratio; CI: confidence interval.

Table 3. Statin use duration in predicting benign prostate enlargement progression in hyperlipidemia patients.

Variable	HR	95%CI	p-Values*
Statin use (>365 days)	0.70	0.58–0.85	<.001
Statin use (181–365 days)	0.98	0.77–1.27	.899
Statin use (91–180 days)	0.99	0.75–1.31	.944
Statin use (31–90 days)	1.07	0.80–1.42	.672
Statins use (none)	1.00
Trend			.001
Statin use (>365 days)^a	0.66	0.54–0.81	<.001
Statin use (181–365 days)^a	0.92	0.72–1.19	.542
Statin use (91–180 days)^a	1.00	0.76–1.33	.978
Statin use (31–90 days)^a	1.13	0.85–1.52	.405
Statin use (none)	1.00
Trend^a			<.001
Statin use (>365 days)^b	0.68	0.56–0.82	<.001
Statin use (181–365 days)^b	0.96	0.75–1.24	.774
Statin use (91–180 days)^b	0.97	0.74–1.28	.836
Statin use (31–90 days)^b	1.05	0.79–1.41	.725
Statin use (none)	1.00
Trend^b			<.001

HR: hazard ratio; CI: confidence interval.

* Evaluated by the Cox proportional hazard regression.

^a Adjusted for age, diabetes mellitus, hypertension, coronary heart disease, metformin use, aspirin use, use of lipid-lowering drugs except statins, and urology visit.

^b Adjusted for propensity score.