Mini-Mental State Examination score and B-type natriuretic peptide as predictors of cardiovascular and total mortality in an elderly general population

Figures & data

Figure 1. Flow chart of the study.

Table I. Base-line characteristics of the participants by survival status.

Characteristic	Survivors (n = 258)	Non-survivors (n = 241)	P value
Age, mean (SD)	78.5 (3.4)	81.4 (4.5)	<0.001
Women, n (%)	182 (75.2)	179 (69.4)	0.126
Body mass index, mean (SD)	27.0 (4.2)	25.8 (4.7)	0.005
Smoking, n (%)	57 (23.7)	73 (28.4)	0.227
NYHA class III or IV (%)	45 (19.0)	73 (30.7)	0.003
MMSE score, median (IQR)	28 (25–29)	25 (23–28)	<0.001
MMSE score < 24 points, n (%)	31 (12.9)	85 (32.9)	<0.001
Dementia at examination, n (%)	8 (3.3)	37 (14.3)	<0.001
Education in years (SD)	6.9 (3.4)	6.8 (3.5)	0.798
Zung's self-rating depression scale (SD)	38.2 (7.7)	40.7 (8.0)	0.001
Medication
Regular medication, n (%)	209 (86.7)	239 (92.6)	0.029
Beta-blockers, n (%)	105 (43.6)	113 (43.8)	0.959
ACE-inhibitors/ARBs, n (%)	45 (18.7)	57 (22.1)	0.344
Diuretics, n (%)	65 (27.0)	112 (43.4)	<0.001
Calcium channel blockers, n (%)	42 (17.4)	44 (17.1)	0.912
Statins, n (%)	20 (8.3)	3 (1.2)	<0.001
Oral diabetes medication, n (%)	12 (5.0)	24 (9.3)	0.062
Insulin, n (%)	7 (2.9)	10 (3.9)	0.550
Previous illnesses
Previous myocardial infarction, n (%)	70 (29.0)	95 (36.8)	0.065
Hypertension, n (%)	157 (65.1)	143 (55.4)	0.084
Heart failure, n (%)	39 (16.2)	84 (28.6)	<0.001
Atrial fibrillation, n (%)	28 (11.6)	48 (18.6)	0.030
Diabetes, n (%)	41 (17.0)	62 (24.0)	0.053
Previous stroke, n (%)	11 (4.6)	38 (14.7)	<0.001
Heart rate per minute (SD) bpm	68.4 (13.7)	68.7 (13.2)	0.834
Blood pressure, systolic (SD) mmHg	157.2 (23.7)	147.7 (23.9)	<0.001
Blood pressure, diastolic (SD) mmHg	78.2 (10.0)	74.7 (11.4)	<0.001
Laboratory data
Hemoglobin, mean (SD) g/L	134.9 (11.7)	131.8 (13.6)	0.006
BNP, median (IQR) pmol/L	27.3 (16.2–47.9)	48.6 (24.0–86.5)	<0.001
Creatinine clearance, mean (SD) mL/min	55.3 (14.7)	49.4 (15.6)	<0.001
fP-gluc, mean (SD) mmol/L	5.5 (1.2)	5.7 (1.4)	0.352
Lipids
Cholesterol, mean (SD) mmol/L	5.90 (1.08)	5.50 (1.17)	0.001
LDL cholesterol, mean (SD) mmol/L	4.00 (0.98)	3.80 (1.12)	0.002
HDL cholesterol, mean (SD) mmol/L	1.55 (0.40)	1.40 (0.41)	<0.001
Triglycerides, median (IQR) mmol/L	1.32 (0.95–1.30)	1.32 (0.97–1.78)	0.738

SD = standard deviation; NYHA = New York Heart Association class reclassified as I–II and III–IV; IQR = interquartile range; MMSE = Mini-Mental State Examination; ACE = angiotensin-converting enzyme; ARB = angiotensin II receptor blocker; BNP = B-type natriuretic peptide; fP-gluc = fasting plasma glucose; LDL = low-density lipoprotein; HDL = high-density lipoprotein.

Table II. Hazard ratios for total and cardiovascular mortality during the median follow-up of 7.9 years according to base-line BNP and MMSE score (n = 499).

	HR (95% CI) per 1-SD increase in log variable	P value	HR (95% CI) for values above the 80th percentile for BNP^a and below the 20th percentile for MMSE^b score	P value
Total mortality
BNP
Unadjusted model	1.64 (1.44–1.87)	<0.001	2.63 (2.00–3.44)	<0.001
Age- and sex-adjusted model	1.47 (1.30–4.06)	<0.001	2.17 (1.65–2.86)	<0.001
Multivariable model^c	1.44 (1.22–1.70)	<0.001	1.85 (1.28–2.66)	0.001
MMSE score
Unadjusted model	0.65 (0.58–0.73)	<0.001	2.32 (1.79–3.01)	<0.001
Age- and sex-adjusted model	0.74 (0.65–0.84)	<0.001	1.82 (1.38–2.41)	<0.001
Multivariable model^c	0.81 (0.70–0.94)	0.007	1.40 (1.00–1.97)	0.048
Cardiovascular mortality
BNP
Unadjusted model	1.84 (1.56–2.18)	<0.001	3.01 (2.11–4.29)	<0.001
Age- and sex-adjusted model	1.65 (1.38–1.97)	<0.001	2.40 (1.65–3.43)	<0.001
Multivariable model^c	1.72 (1.37–2.15)	<0.001	2.18 (1.32–3.56)	0.002
MMSE score
Unadjusted model	0.68 (0.58–0.79)	<0.001	2.21 (1.55–3.17)	<0.001
Age- and sex-adjusted model	0.81 (0.68–0.96)	0.017	1.62 (1.1–2.38)	0.013
Multivariable model^c	0.92 (0.75–1.14)	0.437	1.11 (0.70–1.76)	0.659

^aHazard ratio for participants with values above the 80th percentile relative to the rest of the participants, the 80th percentile corresponding to values 79.7 pg/mL or more for BNP.

^bHazard ratio for participants with values below the 20th percentile relative to the rest of the participants, the 20th percentile corresponding to values fewer than 24 points in MMSE score.

^cIn the multivariable model were included all the parameters with P < 0.100 in Table I. Because of mutual dependency, only one of the lipid parameters, HDL, was included. Similarly, only systolic blood pressure was included. Adjustment for age, body mass index, New York Heart Association class I–II or III–IV, heart failure, systolic blood pressure, hypertension, previous myocardial infarction, atrial fibrillation, stroke, diabetes, hemoglobin, high-density lipoprotein, creatinine clearance, as well as adjustment for MMSE in analysis for BNP and adjustment for BNP in analysis for MMSE.

BNP = B-type natriuretic peptide; MMSE = Mini-Mental State Examination; HR = hazard ratio; CI = confidence interval.

Figure 2. Age- and sex-adjusted Cox proportional hazards survival curves for total and cardiovascular mortality divided by B-type natriuretic peptide (BNP) and Mini-Mental State Examination test (MMSE) quintiles (I–V), separately, in the entire study population (n = 499). A: BNP and total mortality (P for trend < 0.001). B: MMSE and total mortality (P < 0.001). C: BNP and cardiovascular mortality (P < 0.001). D: MMSE and cardiovascular mortality (P = 0.067). The BNP quintiles were 3.2–17.0, 17.2–28.0, 28.2–45.3, 46.2–78.8, and 79.7–500 pg/mL. The MMSE score quintiles were 18–23, 24–25, 26–27, 28, and 29–30.