Long-term lithium treatment in bipolar disorder: effects on glomerular filtration rate and other metabolic parameters

International Journal of Bipolar Disorders

Table 5 Measures associated with vs. without low eGFR among 2669 assays in 312 bipolar disorder subjects treated long-term with lithium

Measure	Low eGFR^a	Normal eGFR	p-value [χ ² or t-score]
Age at assay	62.7 [61.4–64.0]	48.0 [47.5–48.5]	<0.0001 [18.3]
Medical comorbidity (%)^b	83.5	59.5	<0.0001 [41.3]
Lithium exposure
Years treated	19.6 [18.5–20.7]	11.2 [10.9–11.5]	<0.0001 [16.3]
Mean dose	588 [554–622]	884 [871–896]	<0.0001 [15.5]
Mean serum [Li+]	0.65 [0.63–0.68]	0.66 [0.65–0.67]	0.32 [0.99]
Physiological measures
BUN	36.7 [34.3–39.1]	24.6 [24.0–25.2]	<0.0001 [12.6]
[Glucose]	108 [103–112]	95.8 [94.4–97.2]	<0.0001 [5.88]
BMI	28.5 [26.2–30.8]	26.4 [25.9–26.9]	0.03 [2.22]

Means are with 95% CI. Serum lithium concentration is in mEq/L; dose is of lithium carbonate is total mg/day. Additional factors not associated with low eGFR: (1) diagnosis (bipolar I vs. bipolar II), (2) education, (3) metabolic syndrome (overall risk = 30.4%), (4) any substance abuse, (5) alcohol abuse, (6) smoking, (7) any suicidal act, (8) serum TSH. Medical illnesses include cardiovascular and metabolic syndromes
^aLow eGFR: subjects with at least one value <60 mL/min/1.73 m²; the observed rate of such subjects was 92/312 (29.5%), but 312/2669 assays (11.3%)
^bMost frequent medical comorbidities are: cardiovascular diseases, diabetes, hypercholesterolemia, hypertension, hypertriglyceridemia, hypothyroidism, and respiratory diseases