Abstract
Hypertension (HTN) and dyslipidemia are major risk factors for coronary heart disease (CHD). In 676 (projected to 26.1 million) US persons from the National Health and Nutrition Examination Survey (NHANES) 2001–2002 with HTN, the authors estimated the preventable CHD events from statistical control of blood pressure (BP) and lipid levels. Using Framingham algorithms, the authors projected the CHD events that could be prevented from statistical control of BP, low‐density lipoprotein cholesterol, and high‐density lipoprotein cholesterol. If BP was controlled to nominal levels, the authors projected 19% of CHD events (37% if controlled to optimal) would be prevented. Improving lipid levels to nominal levels was estimated to prevent 27% of CHD events (62% if controlled to optimal). Combined control of BP and lipid levels to nominal levels was projected to prevent 38% of CHD events (76% if controlled to optimal). The authors' results demonstrate that combined control of BP and lipid levels may prevent the majority of CHD events in Americans with HTN.
Hypertension (HTN) and dyslipidemia (DYS) represent highly prevalent conditions in the US population, the control of which can substantially reduce the future risk of cardiovascular events and mortality. 1 , 2 The most recently available reports from the US National Health and Nutrition Examination Survey (NHANES) note the prevalence, treatment, and control rates of HTN in 1999 and 2000 to be 29%, 58%, and 31%, respectively, among US adults. 3 Moreover, only 35% of individuals in the same period were noted to be aware of their DYS, only 12% were on treatment, and only 5% had total cholesterol controlled to <200 mg/dL. 4 Recently reported data from NHANES 2001–2002 note the prevalence of combined HTN and DYS to be 16.4% in men and 20.2% in women and range from <10% in persons younger than 40 years to >50% in persons aged 60 years or older. 5 Clinical trials have frequently reported on the efficacy of controlling HTN and DYS as individual conditions. 1 , 6
The present investigation aims to examine, through statistical projections of global risk, the proportion of coronary heart disease (CHD) events potentially preventable by control of both blood pressure (BP) and lipid levels in persons with HTN in the adult US population in 2001 and 2002 and the variation in these estimates when stratified by sex, age group, ethnicity, and cardiovascular risk status.
METHODS
We identified adults aged 30 to 74 years from the NHANES 2001–2002 population with HTN (N=676, projected to 26.1 million, 54.1% female) who had complete BP and lipid data, without prior cardiovascular disease (self‐reported history of heart attack, stroke, or heart failure). HTN was defined as BP ≥140 mm Hg systolic or ≥90 mm Hg diastolic ≥130 mm Hg systolic or ≥80 mm Hg diastolic in patients with diabetes mellitus [DM]), or self‐reported use of medication for HTN. BP was measured using a mercury sphygmomanometer and reported as the average of 4 readings. HTN treatment was defined by self‐report. Low‐density lipoprotein cholesterol (LDL‐C) level was obtained directly or was calculated using the Friedwald equation (LDL‐C = total cholesterol – high‐density lipoprotein cholesterol [HDL‐C] – [1/5] triglycerides) if triglyceride level was <400 mg/dL. Detailed specimen and data collection are discussed in the NHANES Laboratory/Medical Technologists Procedures Manual. 7
DM was defined as a fasting glucose level ≥6.99 mmol/L (126 mg/dL) with a nonfasting glucose level of ≥11.1 mmol/L (200 mg/dL), or as receiving oral hypoglycemic medication or insulin, or as self‐reported DM. Persons with prior cardiovascular disease (CVD) were not included in the analysis because application of the Framingham risk algorithms used in this report was not appropriate in such individuals.
Among those who fit the above criteria for HTN, we applied the Framingham risk prediction algorithms 8 to provide an estimate of the 10‐year probability of CHD. Analyses were stratified by sex, age group (30–39, 40–49, 50–59, and 60–74 years), race (Hispanic, non‐Hispanic white, non‐Hispanic black), and risk status (HTN uncomplicated, no other risk factors; HTN moderate risk, 1 or 2 other risk factors; HTN complicated, ≥3 other risk factors or comorbid DM). Other risk factors include the following: (1) age older than 45 years in men or older than 55 years in women; (2) smoking; (3) HDL‐C, <40 mg/dL; and (4) LDL‐C, ≥130 mg/dL ≥100 mg/dL if comorbid DM is present). These equations are only applicable for use in persons aged 30 to 74 years; thus, persons younger or older than this age range were not included in the present study. The estimated number of CHD events predicted in 10 years in the uncontrolled population (those with BP ≥140 mm Hg systolic or ≥90 mm Hg diastolic [or ≥130 mm Hg systolic or ≥80 mm Hg diastolic if comorbid DM is present]) was calculated by multiplying the 10‐year calculated CHD risk for each group with the weighted population size. Similarly, the controlled population (as defined according to nominal and optimal levels of control for BP only, lipid levels only, and both BP and lipid levels in the paragraph below) estimated number of CHD events was calculated by multiplying the 10‐year calculated CHD modified risk with the weighted population size. The number of events prevented was defined as the difference between the uncontrolled population and the controlled population. Percent of attributable risk (PAR) is the ratio of the number of events prevented and the total number of uncontrolled population events predicted in 10 years, multiplied by 100.
We initially examined the effect of modifying BP to nominal (<140/90 mm Hg, <130/80 mm Hg in those with DM) and then to optimal (<120/80 mm Hg) levels of control. Each intervention involved resetting the Framingham coefficients in all patients to the coefficients representing the controlled range and recalculating CHD risk. Next, we examined the effect of modifying lipid levels to nominal levels (LDL‐C <130 mg/dL or <100 mg/dL if comorbid DM or >20% 10‐year CHD risk is present; HDL‐C >45 mg/dL) and then to optimal levels (LDL‐C <100 mg/dL and HDL >60 mg/dL) of control. Last, we examined the preventable CHD events associated with nominal or optimal control of both BP and lipid levels.
SAS statistical software version 9.1.3 (SAS Institute, Inc, Cary, NC) as well as SUDAAN software (RTI International, Research Triangle Park, NC) were used for analysis and computation of weighted estimates for projection to the adult population of the United States.
RESULTS
Table I shows mean levels of BP and lipids and other risk factors among men and women with HTN. Women with HTN were significantly older than men (P<.05). While average systolic BP was similar in men (140 mm Hg) and women (141 mm Hg), diastolic BP was significantly higher in men (81 mm Hg) than in women (78 mm Hg) (P<.01). Women had significantly higher HDL‐C (57 mg/dL) than did men (47 mg/dL) (P<.01). Men had significantly higher triglyceride levels (171 mg/dL) than did women (148 mg/dL) (P<.01); more women were in the HTN uncomplicated risk group (15.8%) compared with men (4.4%), while more men were in the HTN complicated risk group (30.2%) compared with women (19.1%) (P<.01).
Table I.
Mean (±SD) and Prevalence of Risk Factors in Persons With HTN (Without Prior CVD)
| Risk Factors | Overall (N=676, Projected to 26.1 Million) | Men (n=313, Projected to 12.0 Million) | Women (n=363, Projected to 14.1 Million) |
|---|---|---|---|
| Age, y | 56±11.7 | 55±12.0 | 58±11.4a |
| Systolic BP, mm Hg | 140±19.5 | 140±18.9 | 141±20.0 |
| Diastolic BP, mm Hg | 79±12.7 | 81±13.2 | 78±11.4b |
| LDL‐C, mg/dL | 128±34.8 | 127±34.4 | 129±12.0 |
| HDL‐C, mg/dL | 52±16.1 | 47±12.5 | 57±35.2b |
| Triglyceride level, mg/dLc | 159±111.7 | 171±129.6 | 148±17.2b |
| Smoking, % | 24.3 | 27.8 | 21.4 |
| Diabetes mellitus, % | 14.9 | 17.8 | 12.5 |
| HTN Uncomplicated, %d | 10.5 | 4.4 | 15.8b |
| HTN Moderate risk, %d | 65.3 | 65.4 | 65.1 |
| HTN Complicated, %d | 24.2 | 30.2 | 19.1b |
| a P<.05, compared with men. b P<.01, compared with men. cExcludes triglyceride levels >1000 mg/dL. dSee text for definitions. Abbreviations: HTN, hypertension; CVD, cardiovascular disease; BP, blood pressure; LDL‐C, low‐density lipoprotein cholesterol; HDL‐C, high‐density lipoprotein cholesterol. | |||
Initially, we identified 313 men (projected to 12.0 million; calculated 10‐year CHD risk, 16.7%) and 363 women (projected to 14.1 million; calculated 10‐year CHD risk, 5.1%) who fit the above criteria for HTN. Over 10 years, we projected that 2 million events in men and 0.7 million events in women would occur in this uncontrolled population. Moreover, across races, 0.26 million events would be expected to occur in Hispanic persons, 1.99 million in non‐Hispanic whites, and 0.33 million in non‐Hispanic blacks. Across disease groups, most events would be expected to occur in those with HTN moderate risk (1.73 million) and HTN complicated (0.9 million), compared with those with uncomplicated HTN (no additional factors) (0.09 million).
When controlling BP levels to nominal levels of <140/90 mm Hg (<130/80 mm Hg in persons with DM), 10‐year CHD risk was estimated to be reduced to 13.6% with a projected number of 0.37 million events prevented in men, which translated to a PAR of 19%; risk was estimated to be reduced to 4.1% in women with 0.15 million events prevented (PAR, 20%). If BP was reduced to optimal levels (<120/80 mm Hg in everyone), there was a projected decrease in 10‐year CHD risk to 11.1%, with 0.67 million events prevented in men (PAR, 33.6%) and a projected decrease to 2.7%, with 0.38 million events prevented in women (PAR, 47.9%; Table II). The PAR estimates for BP control appeared to be greatest for women aged 60 to 74 years (23.1% for nominal control and 50.6% for optimal control) compared with those in younger age groups (13%–20% for nominal control and 39%–47% for optimal control) and for Hispanic persons (20.3% for nominal control and 35.4% for optimal control); otherwise, there were no significant differences among age, other ethnic, or risk groups (Table II).
Table II.
Estimated CHD Events Predicted Over 10 Years in Patients With HTN (Without Prior CVD), Before and After Controlling Blood Pressure Only
| Weighted Population | Uncontrolled Population | Controlled to Nominal a | No. Estimated Events Prevented | Controlled to Optimal b | No. Estimated Events Prevented | ||||
|---|---|---|---|---|---|---|---|---|---|
| CHD Risk | Events | CHD Risk (Events) | Events | PAR, % | CHD Risk (Events) | Events | PAR, % | ||
| Overall | 26,058,333 | 0.1043 | 2,717,337 | 0.0845 (2,201,054) | 516,283 | 19.00 | 0.0653 (1,701,401) | 1,015,936 | 37.39 |
| Age | |||||||||
| Men | |||||||||
| 30–39 y | 2,001,594 | 0.0907 | 181,597 | 0.0732 (146,603) | 34,993 | 19.27 | 0.0578 (115,762) | 65,835 | 36.25 |
| 40–49 y | 3,881,388 | 0.1162 | 451,156 | 0.0937 (363,726) | 87,430 | 19.38 | 0.0731 (283,886) | 167,270 | 37.08 |
| 50–59 y | 2,952,769 | 0.1769 | 522,376 | 0.1445 (426,535) | 95,841 | 18.35 | 0.1189 (351,217) | 171,160 | 32.77 |
| 60–74 y | 3,131,783 | 0.2676 | 838,061 | 0.2192 (686,521) | 151,541 | 18.08 | 0.1830 (573,158) | 264,903 | 31.61 |
| Total | 11,967,534 | 0.1665 | 1,993,190 | 0.1356 (1,623,385) | 369,805 | 18.55 | 0.1106 (1,324,023) | 669,167 | 33.57 |
| Women | |||||||||
| 30–39 y | 1,637,147 | 0.0110 | 18,061 | 0.0096 (15,686) | 2,375 | 13.15 | 0.0067(11,009) | 7,052 | 39.04 |
| 40–49 y | 3,252,147 | 0.0321 | 104,505 | 0.0267 (86,901) | 17,604 | 16.85 | 0.0182 (59,045) | 45,460 | 43.50 |
| 50–59 y | 4,158,872 | 0.0619 | 257,435 | 0.0506 (210,476) | 46,959 | 18.24 | 0.0331 (137,470) | 119,966 | 46.60 |
| 60–74 y | 5,042,634 | 0.0682 | 344,144 | 0.0525 (264,606) | 79,537 | 23.11 | 0.0337 (169,853) | 174,291 | 50.64 |
| Total | 14,090,800 | 0.0514 | 724,146 | 0.0410 (577,669) | 146,477 | 20.23 | 0.0268 (377,377) | 346,769 | 47.89 |
| Race | |||||||||
| Hispanic | 2,463,935 | 0.1067 | 262,806 | 0.0850 (209,395) | 53,411 | 20.32 | 0.0689 (169,748) | 93,057 | 35.41 |
| Non‐Hispanic white | 18,678,242 | 0.1067 | 1,993,693 | 0.0869 (1,623,221) | 370,472 | 18.58 | 0.0670 (1,252,230) | 741,463 | 37.19 |
| Non‐Hispanic black | 3,478,518 | 0.0937 | 326,006 | 0.0757 (263,296) | 62,710 | 19.24 | 0.0569 (198,068) | 127,939 | 39.24 |
| Disease groupc | |||||||||
| HTN Uncomplicated | 2,747,825 | 0.0333 | 91,529 | 0.0266(73,155) | 18,374 | 20.07 | 0.0190 (52,302) | 39,227 | 42.86 |
| HTN Moderate risk | 17,005,024 | 0.1018 | 1,730,433 | 0.0828 (1,407,950) | 322,483 | 18.64 | 0.0618 (1,051,679) | 678,754 | 39.22 |
| HTN Complicated | 6,305,483 | 0.1420 | 895,374 | 0.1142(719,950) | 175,424 | 19.59 | 0.0947 (597,419) | 297,955 | 33.28 |
| aNominal control defined as blood pressure <l40/90 mm Hg (or <130/80 mm Hg if comorbid diabetes mellitus [DM] is present). bOptimal control defined as blood pressure <120/80 mm Hg. cSee text for definitions. Abbreviations: CHD, coronary heart disease; HTN, hypertension; CVD, cardiovascular disease; PAR, percent of attributable risk. | |||||||||
The effect of reducing lipid levels to nominal levels (LDL‐C <130 mg/dL; or <100 mg/dL if comorbid CHD, comorbid DM, or >20% 10‐year CHD risk is present; and HDL >45 mg/dL) resulted in the possible prevention of 24.2% of CHD events in men and 35.6% of events in women, corresponding to 0.48 million and 0.26 million events prevented, respectively. Further reduction to optimal lipid levels resulted in the estimated prevention of 61.6% of events (1.23 millions) in men and 63.0% of events (0.46 millions) in women (Table III). PAR estimates for control to nominal levels tended to be highest among women aged 60–74 (38.0%), non‐Hispanic blacks (27.3%), and individuals with complicated HTN (36.1%). However, for optimal control of lipids, PAR estimates tended to be highest among younger men and women aged 30–39 (66.0%[M], 67.1%[F]), and those with complicated HTN (62.7%). (Table III).
Table III.
Estimated CHD Events Predicted Over 10 Years in Patients With HTN (Without Prior CVD), Before and After Controlling Lipid Levels Only
| Population | Uncontrolled Population | Controlled to Nominal a | No. Estimated Events Prevented | Controlled to Optimal b | No. Estimated Events Prevented | ||||
|---|---|---|---|---|---|---|---|---|---|
| CHD Risk | Events | CHD Risk (Events) | Events | PAR, % | CHD Risk (Events) | Events | PAR, % | ||
| Overall | 26,058,333 | 0.1043 | 2,717,337 | 0.0759 (1,977,460) | 739,877 | 27.23 | 0.0397 (1,034,052) | 1,683,285 | 61.95 |
| Age | |||||||||
| Men | |||||||||
| 30–39 y | 2,001,594 | 0.0907 | 181,597 | 0.0634 (126,904) | 54,692 | 30.12 | 0.0308 (61,742) | 119,855 | 66.00 |
| 40–49 y | 3,881,388 | 0.1162 | 451,156 | 0.0907 (352,217) | 98,939 | 21.93 | 0.0438 (169,817) | 281,340 | 62.36 |
| 50–59 y | 2,952,769 | 0.1769 | 522,376 | 0.1295 (382,376) | 140,000 | 26.80 | 0.0647 (190,963) | 331,413 | 63.44 |
| 60–74 y | 3,131,783 | 0.2676 | 838,061 | 0.2074 (649,685) | 188,376 | 22.48 | 0.1097 (343,540) | 494,521 | 59.01 |
| Total | 11,967,534 | 0.1665 | 1,993,190 | 0.1263 (1,511,182) | 482,008 | 24.18 | 0.0640 (766,062) | 1,227,128 | 61.57 |
| Women | |||||||||
| 30–39 y | 1,637,147 | 0.0110 | 18,061 | 0.0070 (11,480) | 6,581 | 36.44 | 0.0036 (5,951) | 12,110 | 67.05 |
| 40–49 y | 3,252,147 | 0.0321 | 104,505 | 0.0218 (70,919) | 33,587 | 32.14 | 0.0118 (38,528) | 65,978 | 63.13 |
| 50–59 y | 4,158,872 | 0.0619 | 257,435 | 0.0410 (170,523) | 86,913 | 33.76 | 0.0228 (94,724) | 162,711 | 63.20 |
| 60–74 y | 5,042,634 | 0.0682 | 344,144 | 0.0423 (213,356) | 130,787 | 38.00 | 0.0255 (128,787) | 215,356 | 62.58 |
| Total | 14,090,800 | 0.0514 | 724,146 | 0.0331 (466,277) | 257,869 | 35.61 | 0.0190 (267,990) | 456,156 | 62.99 |
| Race | |||||||||
| Hispanic | 2,463,935 | 0.1067 | 262,806 | 0.0790 (194,763) | 68,043 | 25.89 | 0.0407 (100,334) | 162,472 | 61.82 |
| Non‐Hispanic white | 18,678,242 | 0.1067 | 1,993,693 | 0.0780 (1,456,384) | 537,310 | 26.95 | 0.0401 (748,353) | 1,245,340 | 62.46 |
| Non‐Hispanic black | 3,478,518 | 0.0937 | 326,006 | 0.0682 (237,106) | 88,900 | 27.27 | 0.0365 (126,999) | 199,007 | 61.04 |
| Disease Group | |||||||||
| HTN Uncomplicated | 2,747,825 | 0.0333 | 91,529 | 0.0269 (73,817) | 17,712 | 19.35 | 0.0147 (40,349) | 51,180 | 55.92 |
| HTN Moderate risk | 17,005,024 | 0.1018 | 1,730,433 | 0.0783 (1,331,692) | 398,741 | 23.04 | 0.0388 (659,242) | 1,071,191 | 61.90 |
| HTN Complicated | 6,305,483 | 0.1420 | 895,374 | 0.0907 (571,951) | 323,422 | 36.12 | 0.0530 (334,460) | 560,913 | 62.65 |
| aNominal control defined as low‐density lipoprotein cholesterol (LDL‐C) <130 mg/dL (<100 mg/dL if diabetes mellitus [DM] or >20% 10‐year coronary heart disease [CHD] risk is present) and high‐density lipoprotein cholesterol (HDL‐C) >45 mg/dL. bOptimal control defined as LDL‐C <100 mg/dL and HDL‐C >60 mg/dL. Abbreviations: HTN, hypertension; CVD, cardiovascular disease; PAR, percent of attributable risk. | |||||||||
Simultaneous control of BP, LDL‐C, and HDL‐C to nominal levels might prevent 38.2% of events (0.76 million) in men and 38.4% of events (0.28 million) in women; control of all 3 values to optimal levels, on the other hand, could possibly prevent 75.2% of events in men (1.50 million) and 77.1% in women (0.56 million). PAR estimates for nominal control were highest in younger men (44.0%), Hispanic persons (39.5%), and high‐risk individuals (47.6%); for optimal control, PAR estimates were similar regardless of age group, sex, race, or disease group (Table IV).
Table IV.
Estimated CHD Events Predicted Over 10 Years in Patients With HTN (Without Prior CVD), Before and After Controlling for Both BP and Lipid Levels
| Population | Uncontrolled Population | Controlled to Nominal a | No. Estimated Events Prevented | Controlled to Optimal b | No. Estimated Events Prevented | ||||
|---|---|---|---|---|---|---|---|---|---|
| CHD Risk | Events | CHD Risk (Events) | Events | PAR, % | CHD Risk (Events) | Events | PAR, % | ||
| Overall | 26,058,333 | 0.1043 | 2,717,337 | 0.0643 (1,676,731) | 1,040,606 | 38.30 | 0.0254 (660,649) | 2,056,688 | 75.69 |
| Age | |||||||||
| Men | |||||||||
| 30–39 y | 2,001,594 | 0.0907 | 181,597 | 0.0508 (101,623) | 79,974 | 44.04 | 0.0190 (38,023) | 143,574 | 79.06 |
| 40–49 y | 3,881,388 | 0.1162 | 451,156 | 0.0733 (284,504) | 166,652 | 36.94 | 0.0278 (107,756) | 343,400 | 76.12 |
| 50–59 y | 2,952,769 | 0.1769 | 522,376 | 0.1062 (313,682) | 208,695 | 39.95 | 0.0419 (123,841) | 398,535 | 76.29 |
| 60–74 y | 3,131,783 | 0.2676 | 838,061 | 0.1696 (531,176) | 306,886 | 36.62 | 0.0719 (225,025) | 613,036 | 73.15 |
| Total | 11,967,534 | 0.1665 | 1,993,190 | 0.1029 (1,230,984) | 762,206 | 38.24 | 0.0413 (494,645) | 1,498,546 | 75.18 |
| Women | |||||||||
| 30–39 y | 1,637,147 | 0.0110 | 18,061 | 0.0068 (11,154) | 6,907 | 38.24 | 0.0025 (4,013) | 14,048 | 77.78 |
| 40–49 y | 3,252,147 | 0.0321 | 104,505 | 0.0209 (67,902) | 36,603 | 35.03 | 0.0076 (24,639) | 79,867 | 76.42 |
| 50–59 y | 4,158,872 | 0.0619 | 257,435 | 0.0391 (162,669) | 94,767 | 36.81 | 0.0141 (58,784) | 198,652 | 77.17 |
| 60–74 y | 5,042,634 | 0.0682 | 344,144 | 0.0405 (204,023) | 140,120 | 40.72 | 0.0156 (78,569) | 265,575 | 77.17 |
| Total | 14,090,800 | 0.0514 | 724,146 | 0.0316 (445,748) | 278,398 | 38.44 | 0.0118 (166,004) | 558,142 | 77.08 |
| Race | |||||||||
| Hispanic | 2,463,935 | 0.1067 | 262,806 | 0.0645 (159,007) | 103,799 | 39.50 | 0.0262 (64,569) | 198,237 | 75.43 |
| Non‐Hispanic white | 18,678,242 | 0.1067 | 1,993,693 | 0.0665 (1,241,870) | 751,824 | 37.71 | 0.0256 (478,245) | 1,515,448 | 76.01 |
| Non‐Hispanic black | 3,478,518 | 0.0937 | 326,006 | 0.0575 (200,047) | 125,959 | 38.64 | 0.0227 (79,036) | 246,970 | 75.76 |
| Disease groups | |||||||||
| HTN Uncomplicated | 2,747,825 | 0.0333 | 91,529 | 0.0239 (65,737) | 25,792 | 28.18 | 0.0092 (25,302) | 66,226 | 72.36 |
| HTN Moderate risk | 17,005,024 | 0.1018 | 1,730,433 | 0.0671 (1,141,462) | 588,971 | 34.04 | 0.0242 (412,086) | 1,318,347 | 76.19 |
| HTN Complicated | 6,305,483 | 0.1420 | 895,374 | 0.0745 (469,533) | 425,840 | 47.56 | 0.0354 (223,260) | 672,113 | 75.07 |
| aNominal control defined as blood pressure <l40/90 mm Hg (or <130/80 mm Hg if comorbid diabetes mellitus [DM] is present), low‐density lipoprotein cholesterol (LDL‐C) <130 mg/dL (or <100 mg/dL if comorbid DM, or >20% 10‐year coronary heart disease [CHD] risk is present), and high‐density lipoprotein cholesterol (HDL‐C) >45 mg/dL. Optimal control defined as blood pressure <120/80 mm Hg, LDL‐C <100 mg/dL, and HDL‐C >60 mg/dL. Abbreviations: HTN, hypertension; CVD, cardiovascular disease; PAR, percent of attributable risk. | |||||||||
DISCUSSION
We report that nearly 80% of CHD events might potentially be prevented with optimal control of BP and lipid levels (including LDL‐C and HDL‐C) in US adults with HTN. These effects from combined BP and lipid control are similar regardless of sex (although a higher proportion of CHD events in women appear preventable from optimal BP control), race, and risk group. While the proportion of preventable events appears similar by age group, BP and/or lipid control might possibly prevent substantially more CHD events in older persons (eg, in men more than a 4‐fold and in women more than a 10‐fold greater number of preventable events in the 60–74 vs the 30–39 age group) owing to the higher absolute risk of CHD in older persons. Our results compare closely with those of a previous report that examined the impact of combined BP and lipid control in persons specifically with the metabolic syndrome among US adults surveyed from 1988 through 1994, where optimal control of BP, LDL‐C, and HDL‐C was predicted to prevent approximately 80% of CHD events. 9 Given the high prevalence of HTN and DYS in the US population, with approximately one‐fifth of all adults having comorbid HTN and DYS (including more than half of persons older than 60 years), an appreciation of the potential benefit of controlling both conditions is needed. The need for a shift in the treatment paradigm from the diagnosis and treatment of individual cardiovascular risk factors to the assessment and management of total cardiovascular risk has been recommended. 10 While a 2006 survey reported that of 41,000 newly diagnosed patients with HTN and DYS from the Veterans Affairs health care system, approximately one‐quarter of asymptomatic patients (and 15% of those with DM) were at goal for BP and LDL‐C 11 ; NHANES 2001–2002 reports this proportion to be closer to one‐tenth. 5 With respect to lipid intervention, previous clinical trials examining effects on angiographically measured disease 12 , 13 (despite their fairly small size) demonstrated that 70% to 90% of CHD events might be preventable from combined statin‐niacin intervention designed to improve both LDL‐C and HDL‐C values.
The major strength of our study was the ability to project to the adult hypertensive US population the potential estimated benefit, in terms of preventable CHD events as a result of achieving optimal levels of BP, LDL‐C, and HDL‐C. A limitation of our study was that risk projections using Framingham risk algorithms (which were based on a predominantly middle‐class white population with baseline risk factors measured in the 1950s) may not be entirely appropriate for use in large contemporary populations such as that in our study. Most important, projections of benefit from adjustment of the equations as we have done, which are based on prospective data, may not reflect the actual impact from clinical interventions (eg, current lipid management involving statins may provide additional risk‐reduction benefit beyond what could be predicted on the basis of LDL‐C reduction in the Framingham risk equations). Moreover, as some lipid or BP values reflect medication effect, projection of risk from the Framingham risk algorithms, which were based primarily on an untreated cohort, may not accurately represent risk in persons who are already being treated (eg, treatment of elevated levels may not reduce event risk to levels associated with untreated optimal levels). Since persons receiving antihypertensive medication are included in the analysis (including those both uncontrolled and controlled to goal levels), the number of initially hypertensive persons and actual benefit in terms of preventable CHD events would probably have been greater had all persons been untreated to begin with.
CONCLUSIONS
Our study demonstrates important potential benefits from the simultaneous control of BP, LDL‐C, and HDL‐C values in American adults with HTN. Given the important gaps remaining in treatment and control of HTN and DYS, a significant number of CHD events in the United States might be prevented by the appropriate and simultaneous control of both conditions. Greater efforts are needed to identify and adequately treat each condition individually and especially to identify individuals who have both conditions, a situation in which the importance of adequate control is even greater because of the likely higher risk of future CHD events these individuals face. Improved physician monitoring, adequate medication titration, and use of combination therapies to adequately control both HTN and DYS are needed.
Acknowledgment and disclosures: The authors wish to express appreciation to Dr Jon Edwards of Envision Pharma Ltd, Scientific Solutions, for his editorial assistance in helping to prepare this manuscript. This study was supported by a contract from Pfizer Inc to the University of California, Irvine. Mr Simon Tang is an employee of Pfizer Inc.
References
- 1. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC0 7 report. JAMA. 2003;289:2560–2572. [DOI] [PubMed] [Google Scholar]
- 2. Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults . Executive Summary of the Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). JAMA. 2001;285:2486–2497. [DOI] [PubMed] [Google Scholar]
- 3. Hajjar I, Kotchen TA. Trends in prevalence, awareness, treatment, and control of hypertension in the United States, 1988–2000. JAMA. 2003;290:199–206. [DOI] [PubMed] [Google Scholar]
- 4. Ford ES, Mokdad AH, Giles WH, et al. Serum total cholesterol concentrations and awareness, treatment, and control of hypercholesterolemia among US adults: findings from the National Health and Nutrition Examination Survey, 1999–2000. Circulation. 2003;107:2185–2189. [DOI] [PubMed] [Google Scholar]
- 5. Wong ND, Lopez V, Tang S, et al. Prevalence, treatment and control of combined hypertension and hypercholesterolemia in adults in the United States. Am J Cardiol. 2006;98:204–208. [DOI] [PubMed] [Google Scholar]
- 6. Grundy SM, Cleeman JI, Merz CN, et al, for the National Heart, Lung, and Blood Institute . American College of Cardiology Foundation; American Heart Association. Implications of recent clinical trials for the National Cholesterol Education Program Adult Treatment Panel III guidelines. Circulation. 2004;110:227–239. [DOI] [PubMed] [Google Scholar]
- 7. National Health and Nutrition Examination Survey (NHANES) 2001–2002. Laboratory/Medical Technologists Procedures Manual. Atlanta, GA: Centers for Disease Control and Prevention; 2005. [Google Scholar]
- 8. Wilson PW, D'Agostino RB, Levy D, et al. Prediction of coronary heart disease using risk factor categories. Circulation. 1998;97:1837–1847. [DOI] [PubMed] [Google Scholar]
- 9. Wong ND, Pio J, Franklin SS, et al. Preventing heart disease by nominal and optimal control of blood pressure and lipids in persons with the metabolic syndrome. Am J Cardiol. 2003;91:1421–1426. [DOI] [PubMed] [Google Scholar]
- 10. Ansell BJ. Evidence for a combined approach to the management of hypertension and dyslipidemia. Am J Hypertens. 2005;18(9, pt 1):1249–1257. [DOI] [PubMed] [Google Scholar]
- 11. Johnson ML, Pietz K, Battleman DS, et al. Therapeutic goal attainment in patients with hypertension and dyslipidemia. Med Care. 2006;44:39–46. [DOI] [PubMed] [Google Scholar]
- 12. Brown G, Albers JJ, Fisher LD. Regression of coronary artery disease as a result of intensive lipid‐lowering therapy in men with high levels of apolipoprotein B. N Engl J Med. 1990;323:1289–1298. [DOI] [PubMed] [Google Scholar]
- 13. Brown BG, Zhao ZQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med. 2001;345:1583–1592. [DOI] [PubMed] [Google Scholar]