Kari Mattila

Serum cystatin C in the aged: relationships with health status

BACKGROUND Serum cystatin C (Cys C) is claimed to be superior to serum creatinine (Cr) in estimating glomerular filtration rate, but its utility in assessing renal function in the polymorbid elderly needs to be evaluated. METHODS In a cross-sectional, community-based survey performed in Lieto in southwestern Finland, Cys C, Cr, and urinary albumin-creatinine ratio (ACR) were measured in 1,260 subjects aged 64 to 100 years. Associations of demographic characteristics and health status factors with levels of Cys C, Cr, and ACR were assessed by means of linear models. RESULTS In men, hypertension, coronary heart disease, urinary infection, rheumatoid arthritis, glucocorticoid treatment, older age, and lower functional status were found to be significant predictors of higher Cys C values, whereas hypertension, coronary heart disease, urinary infection, older age, and increasing body mass index (BMI) significantly predicted higher Cr values. Among women, corresponding factors were hypertension, glucocorticoid treatment, age, functional status, and BMI for Cys C and hypertension, BMI, and age for Cr. Diabetes was significantly associated only with ACR. These factors explained 35% of variation in Cys C values in men and 34.5% in women versus only 14.8% and 11.3% for Cr, respectively. CONCLUSION Glucocorticoid treatment was recognized as an independent Cys C-increasing factor, presumably nonglomerular. In comparison with Cys C, a considerably greater proportion of total variation in Cr values seems to be explained by extrarenal factors.

Serum immunoreactive interleukin‐6 and C‐reactive protein levels in patients with multiple myeloma at diagnosis

Summary Serum bioactive but not immunoreactive interleukin‐6 (IL‐6), and serum C‐reactive protein (CRP), have been reported to be of prognostic significance in multiple myeloma (MM). We measured serum immunoreactive IL‐6 by a sensitive enzyme‐linked immunosorbent assay in 30 MM patients at diagnosis. In 30% of the patients serum immuno‐reactive IL‐6 exceeded the upper reference limit. The concentrations of CRP and IL‐6 showed a linear association. Logarithmically transformed IL‐6, CRP and β2‐microglobulin were significant variables by univariate survival analysis: by multivariate analysis CRP was a slightly stronger prognostic factor than IL‐6 and the only one of independent prognostic significance.

Haematological laboratory findings in the elderly: influence of age and sex

The effects of age and sex on haematological laboratory parameters were studied in connection with a population study in people over the age of 65 years (n = 347). Serum vitamin B12 was the only parameter which decreased significantly with advancing age. Blood leucocyte count, haemoglobin concentration, haematocrit, erythrocyte count, mean erythrocyte volume, mean erythrocyte haemoglobin and serum ferritin values were significantly higher in males than in females. Serum iron, serum transferrin, and plasma and erythrocyte folate levels did not differ between males and females. Thirteen subjects were anaemic and three of them had iron deficiency anaemia. Five subjects had iron deficiency based on serum iron and transferrin but no anaemia. Serum ferritin measurement did not reveal any further subjects with iron deficiency. No case of folate deficiency anaemia was revealed. Although many of the participants were on medication, most of them were living at home and taking care of themselves and represent relatively fit elderly people. Therefore we suggest that these laboratory data can also serve as reference values for the elderly people.

Lipids, lipoproteins and apolipoproteins in the elderly

The lipoprotein components were studied in connection with a population study concerning the state of health and living habits of the elderly people in Turku, Finland. Serum levels of total cholesterol, high density lipoprotein (HDL) cholesterol, triglycerides, apolipoprotein A1 (apo A1) and apolipoprotein B (apo B) of the 347 elderly people (aged 65 years or over) were measured and those of low density lipoprotein (LDL) cholesterol were calculated. The levels of total cholesterol, LDL cholesterol and apo B were significantly higher in females than in males, and the concentrations decreased with advancing age. The concentrations of HDL cholesterol and apo A1 were significantly higher in females than in males but age had no effect. Serum triglycerides behaved differently in males and females; in females age had a significant increasing effect whereas in males no age effect was observed. The apo A1/apo B ratio did not differ between males and females. Reference values of serum lipids, lipoproteins and apolipoproteins of the elderly are suggested.

Blood glycated haemoglobin, serum fructosamine, serum glycated albumin and serum glycated total protein as measures of glycaemia in diabetes mellitus

Blood glycated haemoglobin (HbAlc), serum fructosamine (FA), serum glycated albumin (GA), and serum glycated total protein (GTP) were determined in 61 subjects (19 pregnant women with gestational diabetes, 24 pregnant women with insulin-dependent diabetes mellitus [IDDM] and 18 nonpregnant subjects with IDDM). FA, GA, and GTP correlated with HbAlc similarly (r = 0.791, 0.816, and 0.794, respectively, p < 0.001). In a subgroup of 22 subjects data on blood glucose home monitoring was recorded and used for calculating mean blood glucose as an index of average glycaemia preceding sampling of the glycation products. Mean blood glucose levels preceding sampling of HbAlc by 2 months and FA, GA, or GTP by three weeks correlated significantly with HbAlc (r = 0.668, p < 0.001) and GA (r = 0.441, p < 0.05) whereas no significant correlation was found between mean blood glucose and FA (r = 0.003) or GTP (r = 0.252). In conclusion, such methods which measure specifically the non-enzymatic glycation of a single species of protein (i.e. FPLC for HbAlc and affinity chromatography for GA) are to be preferred for assessing glycaemia.

7.4 Comparison between Finnish and Danish Reference Values for Plasma Proteins

It is well known that genetic mutations may result in varying concentrations of plasma/serum proteins. Further, hormone concentrations and environmental conditions may influence on the plasma protein concentrations. Differences in plasma protein concentrations due to ethnic groups, and geography etc. in the Nordic countries may be investigated by comparing Finnish and Danish reference populations with each other. Both are of Caucasian origin but, from different groups of language and whereas the Finnish climate is belonging to the inland type the Danish climate is typical coastal. The populations in the other Nordic countries, Iceland, Norway, and Sweden, are mainly of the same ethnic group as the Danish, but the climate resembles that of Finland. The most pronounced differences might, therefore, be disclosed by comparing a Danish population with a Finnish one.