Table 3. Linear regression models for cystatin C-based estimated glomerular rate (eGFR) at age 60–64 years (ml/min/1.73 m², dependent variable).

Explanatory variable	n	Coeff	95% CI	P overallA	P for trendA,B
Childhood cognitive function (per 30 unitsC)	1823	1.3	0.6, 2.0	<0.001
Socioeconomic position at age 53 years	1923			<0.001	<0.001
I and II professional and managerial		(ref)
III non-manual		−2.4	−3.9, −0.8
III manual skilled		−3.1	−5.1, −1.0
IV and V manual semi or unskilled		−3.1	−5.8, −0.5
Highest educational attainment	1942			<0.001	<0.001
No qualifications		(ref)
Vocational only		1.8	−0.8, 4.3
Ordinary ('O' level or equivalent)		3.4	1.6, 5.2
Advanced ('A' level or equivalent)		3.1	1.5, 4.7
Higher (degree or equivalent)		4.9	2.8, 7.1
Lifetime smoking	1936			0.003	<0.001
Never smoker		(ref)
Predominantly non-smoker		−0.7	−2.2, 0.8
Predominantly smoker		−1.5	−3.3, 0.3
Lifelong smoker		−3.9	−6.0, −1.8
Self−reported diabetes by age 60–64 years	1877	−3.1	−5.7, −0.5	0.02
On diabetes treatment at age 60–64 years	2052	−3.0	−5.9, −0.1	0.04
HbA1c at age 60–64 years (per %)	1970			<0.001
Linear		−10.4	−15.5, −5.2
Quadratic		0.7	0.3, 1.0
Midlife systolic blood pressure trajectory (Increaser/high vs normal)D	2033	−3.3	−5.9, −0.7	0.01
On anti−hypertensive treatment at age 60–64 years	2052	−3.7	−5.0, −2.4	<0.001
Current systolic blood pressure (per 20 mmHgC)	2033	0.4	−0.3, 1.1	0.21
Current C−reactive protein (per 10 mg/LC)	2045			<0.001
Linear		−3.7	−5.3, −2.1
Quadratic		0.3	0.1, 0.5
Current body mass index (per 5 kg/m2 C)	2030	−2.4	−3.0, −1.7	<0.001
Age at first overweight (years)	1887			<0.001	<0.001
26		−3.8	−5.8, −1.8
36		−4.4	−6.5, −2.3
43		−3.3	−5.4, −1.2
53		−0.5	−2.4, 1.4
60–64		−1.5	−4.0, 0.9
Never		(ref)

^ALikelihood ratio test.

^BOnly reported where appropriate.

^CApproximately 1 standard deviation.

^DLatent trajectories previously derived from systolic blood pressure data at ages 36, 43 and 53 years [18].

All models adjusted for sex and age at cystatin C measurement.