White Coat Hypertension in NIDDM Patients With and Without Incipient and Overt Diabetic Nephropathy

Flemming S Nielsen; Pernille Gæde; Pernille Vedel; Oluf Pedersen; Hans-Henrik Parving

doi:10.2337/diacare.20.5.859

Original Article

White Coat Hypertension in NIDDM Patients With and Without Incipient and Overt Diabetic Nephropathy

Flemming S Nielsen, MD,
Pernille Gæde, MD,
Pernille Vedel, MD,
Oluf Pedersen, MD, DMSC and
Hans-Henrik Parving, MD, DMSC

Steno Diabetes Center Gentofte, Denmark

Address correspondence and reprint requests to Flemming S. Nielsen, MD, Steno Diabetes Center, Niels Stecnsens Vej 2, DK-2820 Gentofte, Denmark.

Diabetes Care 1997 May; 20(5): 859-863. https://doi.org/10.2337/diacare.20.5.859

Abstract

OBJECTIVE Early data have suggested a high prevalence of white coat hypertension (∼ 50%) in NIDDM patients. To study this phenomenon further, we determined the prevalence of white coat hypertension in NIDDM patients with normo- or microalbuminuria or with diabetic nephropathy.

RESEARCH DESIGN AND METHODS Three groups of hypertensive NIDDM patients (repeated clinic blood pressure > 140/90 mmHg or antihypertensive treatment) attending the Steno Diabetes Center were investigated in a cross-sectional study. Group 1 had normoalbuminuria (a urinary albumin excretion [UAE] rate < 30 mg/24 h, n = 30, age 61 ± 7 [mean ± SD] years, 20 men), group 2 had microalbuminuria (UAE rate 30–300 mg/24 h, n = 51, age 55 ± 7 years, 35 men), and group 3 had diabetic nephropathy (UAE rate > 300 mg/24h, n = 47, 62 ± 7 years, 36 men). If given, all previous antihypertensive medication was withdrawn at least 2 weeks before the study (48%). The prevalence of white coat hypertension (clinic hypertension with normal blood pressure values at home) was determined by comparison of clinic blood pressure (Hawksley Random sphygmomanometer) and the ambulatory daytime (7:00 A.M. to 11:00 P.M.) blood pressure (A&D TM2420). By applying established criteria, white coat hypertension was confirmed if daytime blood pressure was < 135/85 mmHg.

RESULTS The clinic blood pressure was 155/86 (SE 3/2) mmHg, 156/89 (2/1) mmHg, and 171/90 (3/2) mmHg in group 1, 2, and 3, respectively (P < 0.05 comparing group 3 with groups 1 and 2). The prevalence of white coat hypertension was significantly higher in group 1 as compared with groups 2 and 3, 23% (95% CI 10–42) vs. 8% (2–19) and 9% (2–20) (P < 0.05), with no difference between the latter two groups.

CONCLUSIONS The prevalence of white coat hypertension in normoalbuminuric NIDDM patients resembles that observed in nondiabetic subjects with essential hypertension, whereas the prevalence is significantly lower in NIDDM patients with incipient or overt diabetic nephropathy, suggesting a difference between primary and secondary hypertension.