Long-term follow-up of patients with elevated serum calcium concentrations in Swedish primary care

Figures & data

Figure 1. Flow chart of patients with elevated calcium concentrations at Tibro Health Care Centre, Sweden, 1995–2000, and re-examination of the patients with elevated and normal calcium concentrations during 2009–2010. Notes: ^§Included in our previous study [3]. ^∆Patients with hypercalcaemia at baseline not included in previous study because of technical problems. ^‡ Two persons only answered the questionnaire, no laboratory samples.

Table I. Characteristics of patients with elevated and normal calcium concentrations, 1995–2000 and 2008–2010, men and women, at Tibro Health Care Centre, Sweden.

	Patients with elevated calcium concentration						Patients with normal calcium concentration						Comparison between patients with elevated and normal calcium concentrations
Variables	Total Mean	Percentile	Men Mean	Percentile	Women Mean	Percentile	Total Mean	Percentile	Men Mean	Percentile	Women Mean	Percentile	Total p-value	Men p-value	Women p-value
1995–2000
Number	127		28		99		254		56		198
Age, 1 January 1995	61.4	36.6, 80.0	55.6	31.8, 77.0	63.0	38.8, 80.2	61.3	36.3, 80.0	55.5	39.0, 80.3	62.9	31.0, 77.0	n.s.	n.s.	n.s.
Age range	18–94		18–82		18–94		18–91		18–82		18–91
S-Calcium^1	2.66	2.56, 2.78	2.72	2.57, 2.88	2.64	2.56, 2.78	2.33	2.21, 2.43	2.31	2.19, 2.42	2.33	2.21, 2.44	< 0.001	< 0.001	< 0.001
2008–2010
Number	63		12		51		133		33		100
Age, 1 January 2011	71.4	49.4, 89.0	67.7	49.2, 80.0	72.3	52.0, 89.0	70.0	45.2, 88.0	66.8	45.2, 84.4	71.0	45.8, 90.0	n.s.	n.s.	n.s.
Age range	31–97		45–82		31–97		30–99		31–99		30–97
P-calcium^2	2.42	2.26, 2.59	2.39	2.18, 2.55	2.43	2.27, 2.64	2.35	2.22, 2.47	2.32	2.21, 2.42	2.36	2.23, 2.48	< 0.001	0.085	0.003
Ionised calcium^3	1.29	1.22, 1.40	1.28	1.24, 1.31	1.29	1.22, 1.44	1.23	1.18, 1.27	1.22	1.16, 1.26	1.23	1.18, 1.28	< 0.001	< 0.001	< 0.001
Creatinine^4	79	57, 122	96	72, 139	75	56, 109	74	52, 98	91	68, 125	69	50, 92	n.s.	n.s.	0.037
Parathyroid hormone^5	68	20, 118	60	14, 136	69	21, 113	58	26, 107	57	22, 104	59	28, 113	n.s.	n.s.	n.s.
Haemoglobin^6	133	114, 149	143	122, 165	131	111, 146	131	116, 148	136	116, 154	129	116, 146	n.s.	n.s.	n.s.
ESR^7	17	3, 49	12	2, 46	18	3, 53	15	3, 33	14	2, 47	15	5, 33	n.s.	n.s.	n.s.
MCV^8	92	86, 99	92	86, 100	92	86, 99	90	85, 95	90	84, 96	90	85, 95	< 0.001	n.s.	0.001
ALP^9	1.2	0.8, 1.6	1.2	0.7, 1.7	1.2	0.8, 1.6	1.2	0.8, 1.7	1.2	0.8, 1.5	1.3	0.8, 1.8	n.s.	n.s.	n.s.
Albumin^10	43	39, 48	44	38, 49	43	40, 48	43	39, 46	43	38, 47	43	40, 46	n.s.	n.s.	n.s.

Notes: Percentile, 10th and 90th percentile. Data are means (SD), n.s. = not significant, Age in years = y. M = man, W = woman, Reference range.

¹Serum calcium analysed in whole blood (mmol/L) 2.15–2.55.

²Plasma calcium (mmol/L)2.15–2.50.

³Ionised calcium (mmol/L) 1.15–1.35.

⁴Creatinine (μmol/L) M 60–100, W 50–90.

⁵Parathyroid hormone (ng/L) 15–65.

⁶Haemoglobin (g/L) M 122–166, W 113–153.

⁷Erythrocyte sedimentation rate (mm) M < 20, W < 30.

⁸MCV = mean corpuscular volume (fL) 82–102.

⁹ALP = alkaline phosphatase (μkat/l) 0.6–1.8.

¹⁰Albumin (g/L) 18–40y 36–48, 41–70 y 36–45, > 70 y 34–45.

Table II. Comparison between diagnoses in percentage of patients with elevated calcium concentrations at first examination in 1995–2000 at Tibro Health Care Centre and diagnoses found after second clinical examination and register investigation in 2009–2010.

	First investigation				Second investigation
	Number	%	Men	Women	Number	%	Men	Women
Primary hyper-parathyroidism	29	23	3	26	46	36	6	40
Parathyroidectomy	11		2	9	20		2	18
Cancer	6^1	5	3	3	15^2	12	7	8
Vitamin D medication	5	4	0	5	15	12	1	14
Sarcoidosis	1	1	1	0	1	1	1	0
Kidney disease	5	4	2	3	14	11	5	9
Lithium treatment	1	1	0	1	2	2	0	2
Transient thyroiditis	2	1	0	2	5	4	0	5
Skeletal disease	8^3	6	3	5	13^4	10	4	9
Unresolved elevated calcium	70	55	16	54	16^5	12	4	12
Total	127	100	28	99	127	100	28	99

Notes: Numbers in italics represent subgroups of diagnoses:

¹1 prostate cancer, 1 breast cancer, 1 small cell lung cancer, 1 myeloma, 1 tonsil cancer, 1 anaplastic thyroid cancer.

²3 prostate cancer, 3 breast cancer, 1 small cell lung cancer, 1 myeloma, 1 tonsil cancer, 1 anaplastic thyroid cancer, 1 hepatic cancer, 1 malignant melanoma, 1 colorectal cancer, 1 pancreatic cancer, 1 ovarian cancer.

³2 osteomalacia, 4 fractures of a vertebra, 1 rib fracture, unfastened hip prosthesis.

⁴2 osteomalacia, 7 fractures of a vertebra, 1 osteitis, 1 rib fracture, 1 unfastened hip prosthesis, 1 RA = rheumatoid arthritis.

⁵12 were dead before the reinvestigation, 2 refused to participate, 2 participated.

Figure 2. Mortality of patients with elevated (≥ 2.56 mmol/L) and normal (≤ 2.46 mmol/L) calcium concentrations, Panel A: men, Panel B: women, at Tibro Health Care Centre in 1995–2000. Mortality in both men and women, Panel C: with different calcium concentrations (≥ 2.56, 2.31–2.46, ≤ 2.30 mmol/L). Note: Censored = follow-up period interrupted.

Table III. Time to death in years in patients with different causes of death: Comparison between patients with elevated and normal calcium concentrations.

	Total		Men		Women
	Mean with 95% CI	N/N	Mean with 95% CI	N/N	Mean with 95% CI	N/N
Total mortality
Elevated Ca^1	11.4 (10.4–12.5)	60/127	10.3 (8.1–12.5)	14/28	11.7 (10.5–12.8)	46/99
Normal Ca^2	11.7 (11.0–12.5)	107/254	12.8 (11.3–14.2)	18/56	11.4 (10.5–12.2)	89/198
p-value^3	0.532		0.109		0.892
Cancer mortality
Elevated Ca^1	14.5 (13.7–15.3)	20/127	12.5 (10.5–14.6)	7/28	14.9 (14.1–15.7)	13/99
Normal Ca^2	15.0 (14.5–15.5)	28/254	15.4 (14.5–16.2)	5/56	14.8 (14.2–15.4)	23/198
p-value^3	0.234		0.039*		0.832
Cardiovascular mortality
Elevated Ca^1	12.8 (11.9–13.8)	40/127	11.9 (9.8–14.0)	9/28	13.0 (11.9–14.0)	31/99
Normal Ca^2	12.4 (11.7–13.1)	88/254	13.1 (11.6–14.5)	16/56	12.1 (11.3–13.0)	72/198
p-value^3	0.572		0.579		0.338

Notes: Mean = mean time (years) to death; CI = confidence interval; N = number of events; n = size of group; Ca = calcium.

¹Patients with elevated calcium concentration.

²Patients with normal calcium concentration.

³Comparisons between patients with normal and elevated calcium concentration l by Log Rank test.

*Statistically significant difference between the two groups.

Dalemo S, Hjerpe P, Bostrom Bengtsson K. Diagnosis of patients with raised serum calcium level in primary care, Sweden. Scand J Prim Health Care 2006;24:160–5.

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