Epidemiology Research International

Research Article

Quality Assessment of 25(OH)D, Insulin, Total Cholesterol, Triglycerides, and Potassium in 40-Year-Old Frozen Serum

Table 2

Descriptive statistics, percentage of change, and correlation for serum concentrations measured in the same 26 subjects (total cholesterol, triglycerides, and potassium) and 29 subjects (insulin), respectively, in 1968-1969 and 2012.


		Baseline samples analyzed in 1968-1969 (same year)			Samples reanalyzed in 2012			Median percentage change ()^b	Spearman rho ()
		Range	Median	Mean (SD)	Range	Median	Mean (SD)	Median percentage change ()^b	Spearman rho ()

Total cholesterol (mmol/L)	26	5.1–7.9	6.5	6.4 (0.74)	3.9–6.9	5.3	5.4 (0.79)	−16.0^***	0.86^***
Triglycerides (mmol/L)	26	0.7–2.4	1.0	1.1 (0.43)	0.8–2.6	1.2	1.3 (0.49)	15.2^***	0.90^***
Potassium (mmol/L)	26	3.6–4.8	4.1	4.1 (0.32)	3.6–5.0	4.2	4.2 (0.28)	3.2^***	0.89^***
Insulin (mU/L)^a	29	3.0–47.0	19	19.7 (10.30)	1.2–31.0	7.8	10.5 (8.70)	−54.0^***	0.74^***

^*** < 0.001.
^aTo convert from mU/L to pmol/L multiply by 6.945.
^bPercentage of change was calculated as (level in 2012 − level at baseline)/level at baseline * 100%. values refer to the Wilcoxon signed rank test.