Risk Factors for Reduced Salivary Flow Rate in a Japanese Population: The Hisayama Study
Table 2
Association of obvious reduction in salivary flow rate with its predictors determined by using logistic regression.
Model 1
Model 2
Obvious reduction in salivary flow rate (%)
PAF (%)
Crude OR (95% CI)
Multivariate ORa (95% CI)
Salivary flow rate (mL/min)
0.98 (0.86–1.11)
NA
NA
Age per decadeb
1.38 (1.16–1.63)
1.25 (1.03–1.51)
NA
NA
Sex (ref. women)
Men
1.28 (0.91–1.80)
1.11 (0.78–1.58)
12.3
9.6
Medical history of stroke
2.82 (1.25–6.40)
2.14 (0.92–4.97)
25.0
3.1
Use of antihypertensive agents
1.31 (0.90–1.91)
13.0
6.3
Smoking habits (ref. noncurrent smoker)
Current smoker
1.08 (0.71–1.67)
11.6
1.4
Alcohol intake (ref. noncurrent drinker)
Current drinker
0.94 (0.67–1.32)
10.6
−3.0
Tooth brushing frequency (ref. twice or more a day)
Once a day
1.31 (0.92–1.87)
12.7
7.6
BMI (ref. <25)
≥25
0.77 (0.51–1.15)
9.1
−6.1
Serum albumin levels [ref. normal (≥4 g/dL)]
Low (<4 g/dL)
1.68 (1.11–2.56)
1.60 (1.04–2.46)
15.8
8.0
2 h postload plasma glucose levels [ref. nondiabetes (<200 mg/dL)]
Diabetes (≥200 mg/dL)
1.24 (0.73–2.10)
12.8
2.1
Dental prosthetic status (ref. ≥20 remaining natural teeth without dentures)
≥20 remaining natural teeth with dentures
1.94 (1.09–3.44)
1.48 (0.81–2.71)
17.4
10.0
<20 remaining natural teeth without dentures
2.36 (1.11–5.05)
2.06 (0.95–4.46)
20.5
<20 remaining natural teeth with dentures
1.25 (0.74–2.13)
0.85 (0.48–1.52)
12.0
Plaque score (ref. <1)
≥1
1.83 (1.28–2.61)
1.53 (1.04–2.24)
15.6
15.6
Periodontal status (ref. non-periodontitis)
Periodontitis
1.45 (1.03–2.03)
1.16 (0.81–1.66)
12.8
15.3
OR: odds ratio; CI: confidence interval; PAF: population attributable fraction; NA: not applicable; BMI: body mass index.
aThe multivariable logistic regression model included sex and all other risk factors with a significance level of < 0.05 in the univariate analysis (model 1).
bAge in years scaled to decades.
